JP3839644B2 - Exchange coupling film, magnetoresistive element using the exchange coupling film, and thin film magnetic head using the magnetoresistive element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention comprises an antiferromagnetic layer and a ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is made constant by an exchange coupling magnetic field generated at the interface between the antiferromagnetic layer and the ferromagnetic layer. In particular, an exchange coupling film capable of obtaining a large exchange coupling magnetic field, a magnetoresistive effect element (spin valve thin film element, AMR element) using the exchange coupling film, and the magnetoresistive effect The present invention relates to a thin film magnetic head using an element.
[0002]
[Prior art]
A spin valve thin film element is a kind of GMR (giant magnetoresistive) element using a giant magnetoresistive effect, and detects a recording magnetic field from a recording medium such as a hard disk.
[0003]
This spin-valve type thin film element has some excellent points such as a relatively simple structure among GMR elements and a resistance change by a weak magnetic field.
[0004]
The spin valve thin film element has the simplest structure, and is composed of an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic intermediate layer, and a free magnetic layer.
[0005]
The antiferromagnetic layer and the pinned magnetic layer are formed in contact with each other, and the magnetization direction of the pinned magnetic layer is made constant by an exchange anisotropic magnetic field generated at the interface between the antiferromagnetic layer and the pinned magnetic layer. Single domain and fixed.
[0006]
The magnetization of the free magnetic layer is aligned in the direction intersecting with the magnetization direction of the pinned magnetic layer by the bias layers formed on both sides thereof.
[0007]
As the antiferromagnetic layer, a Fe—Mn (iron-manganese) alloy film, a Ni—Mn (nickel-manganese) alloy film, a Pt—Mn (platinum-manganese) alloy film, or the like is generally used. However, among these, the Pt—Mn alloy film is particularly in the spotlight because it has various excellent points such as high blocking temperature and excellent corrosion resistance.
[0008]
[Problems to be solved by the invention]
By the way, the present inventors have found that even if a PtMn alloy film is used for the antiferromagnetic layer, the exchange coupling magnetic field generated between the antiferromagnetic layer and the fixed magnetic layer may be small.
[0009]
When a PtMn alloy film is used for the antiferromagnetic layer, the antiferromagnetic layer is transformed from an irregular lattice to a regular lattice by performing a heat treatment after laminating the antiferromagnetic layer and the pinned magnetic layer. Thus, an exchange coupling magnetic field can be generated.
[0010]
However, at the interface between the antiferromagnetic layer and the pinned magnetic layer, there is a one-to-one correspondence between the atoms of the antiferromagnetic material constituting the antiferromagnetic layer and the atoms of the soft magnetic material constituting the pinned magnetic layer. When in a so-called matched state, the antiferromagnetic layer does not appropriately cause the above-described regular transformation, and a large exchange coupling magnetic field cannot be generated.
[0011]
  Conventionally, the above-described matching state is, for example, that of an antiferromagnetic layer.{111}The plane is preferentially oriented in a direction parallel to the interface with the pinned magnetic layer, and similarly the pinned magnetic layer{111}It was thought that this may occur when the crystal orientation of the antiferromagnetic layer and the pinned magnetic layer is the same at the interface, as in the case where the plane is preferentially oriented in a direction parallel to the interface.
[0012]
The present invention is for solving the above-mentioned conventional problems. When an antiferromagnetic material containing element X (X is a platinum group element) and Mn is used as an antiferromagnetic layer, a large exchange anisotropic property is obtained. The present invention relates to an exchange coupling film capable of generating a magnetic field, a magnetoresistance effect element using the exchange coupling film, and a thin film magnetic head using the magnetoresistance effect element.
[0013]
[Means for Solving the Problems]
In the present invention, an antiferromagnetic layer and a ferromagnetic layer are formed in contact with each other, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is constant. In the exchange coupling membrane
The antiferromagnetic layer is formed of an antiferromagnetic material containing element X (where X is one or more of Pt, Pd, Ir, Rh, Ru, and Os) and Mn. And
As for crystal planes oriented in a direction parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer, the same equivalent crystal planes are preferentially oriented, and at least one of the same equivalent crystal axes existing in the crystal plane. The portions are directed in different directions in the antiferromagnetic layer and the ferromagnetic layer.
[0014]
In the present invention, the crystal plane is preferably an equivalent crystal plane typically represented as a {111} plane. The direction of the crystal axis is preferably an equivalent crystal axis direction typically represented as a <110> direction.
[0015]
In the present invention, as described above, the crystal planes oriented in the direction parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer are preferentially oriented to the same equivalent crystal plane. As already described, when the same equivalent crystal plane is preferentially oriented in the direction parallel to the film surface in the antiferromagnetic layer and the ferromagnetic layer, the arrangement of atoms on the antiferromagnetic layer side at the interface, and It tends to be in a so-called matching state in which the arrangement of atoms on the ferromagnetic layer side is in a one-to-one correspondence. As a result, the antiferromagnetic layer does not cause proper regular transformation and cannot generate a large exchange coupling magnetic field. It was considered a thing.
[0016]
However, the present inventors appropriately ordered transformation of the antiferromagnetic layer by heat treatment even when the same equivalent crystal planes of the antiferromagnetic layer and the ferromagnetic layer are preferentially oriented in the direction parallel to the interface, It has been found that a large exchange coupling magnetic field can be obtained.
[0017]
In the present invention, as described above, at least some of the same equivalent crystal axes existing in the crystal plane are oriented in different directions in the antiferromagnetic layer and the ferromagnetic layer.
[0018]
FIG. 14 is a partial perspective view schematically showing the crystal orientation of the antiferromagnetic layer and the ferromagnetic layer constituting the exchange coupling film of the present invention.
[0019]
Reference numeral 4 denotes an antiferromagnetic material formed of an antiferromagnetic material containing element X (where X is one or more of Pt, Pd, Ir, Rh, Ru, and Os) and Mn. Reference numeral 3 denotes a ferromagnetic layer formed of, for example, a NiFe alloy or the like.
[0020]
In the antiferromagnetic layer 4 shown in FIG. 14, the (111) plane is preferentially oriented at the interface with the ferromagnetic layer 3. Similarly, in the ferromagnetic layer 3, the (111) plane is preferentially oriented at the interface.
[0021]
As shown in FIG. 14, the direction of the crystal axis perpendicular to the (111) plane (the c direction in the figure) is the [111] direction, and as described above, the antiferromagnetic layer 4 and the ferromagnetic layer Since the (111) plane of 3 is preferentially oriented in a direction parallel to the interface, the [111] direction of the antiferromagnetic layer 4 and the [111] direction of the ferromagnetic layer 3 are both in the same direction. (C direction in the figure).
[0022]
  Here, the (111) plane indicates a crystal plane (real lattice plane; that is, a reciprocal lattice plane in the diffraction pattern) in the case of a single crystal structure expressed using a Miller index, and is equivalent (equivalent) to the (111) plane. (-111) plane, (1-11) plane, (11-1) plane, (-1-11) plane, (1-1-1) plane, (-11-1) plane as other crystal planes , (-1-1-1) plane exists. In this specification, these equivalent crystal planes are not particularly distinguished, and when one of the equivalent crystal planes is indicated, typically{111}It is written as a surface.
[0023]
The [111] direction and the [110] direction shown below indicate the crystal axis direction of the above-described equivalent crystal plane. The [111] direction includes an equivalent (equivalent) [-111] direction, [11-1] direction, [1-11] direction, [-1-11] direction [1-1-1] direction, [ -11-1] direction and [1-1-1] direction exist, and the [110] direction includes the equivalent [-110] direction, [1-10] direction, and [-1-10] direction. , [-10-1] direction, [101] direction, [−101] direction, [10-1] direction, [011] direction, [01-1] direction, [0-11] direction, [0-1] -1] direction exists. When indicating any of these equivalent crystal axis directions, they are typically described as the <111> direction and the <110> direction.
[0024]
In the exchange coupling film shown in FIG. 14, of the crystal axes existing in the (111) plane, for example, the [110] direction is shown as an example. Facing the direction.
[0025]
However, the [110] direction in the ferromagnetic layer 3 is not directed in the direction a in the figure, but is inclined from the direction a in the figure to the direction b in the figure, so that it is stronger than the [110] direction in the antiferromagnetic layer 4. It can be seen that the [110] directions of the magnetic layer 3 are directed in different directions.
[0026]
As described above, in the exchange coupling film according to the present invention, the crystal planes oriented in the direction parallel to the film surfaces of the antiferromagnetic layer 4 and the ferromagnetic layer 3 are preferentially oriented in the same crystal plane, but in the crystal plane. The anti-ferromagnetic layer 4 and the ferromagnetic layer 3 have a configuration in which at least a part of the same equivalent crystal axis exists in different directions.
[0027]
With such a crystal orientation, the arrangement of atoms on the antiferromagnetic layer 4 side at the interface and the arrangement of atoms on the ferromagnetic layer 3 side do not easily correspond to each other.
[0028]
In the case of having the crystal orientation described above, the antiferromagnetic layer 4 is considered not to be restrained by the crystal structure of the ferromagnetic layer 3 but to have undergone an appropriate regular transformation during heat treatment, which is larger than the conventional one. An exchange coupling magnetic field can be generated.
[0029]
FIG. 15 is a partial perspective view schematically showing the crystal orientation of an exchange coupling film as a comparative example.
[0030]
Reference numeral 31 in this exchange coupling film is an antiferromagnetic material containing element X (where X is one or more of Pt, Pd, Ir, Rh, Ru, and Os) and Mn. Reference numeral 30 denotes a ferromagnetic layer formed of, for example, a NiFe alloy or the like.
[0031]
Similar to the exchange coupling film in FIG. 15, the (111) planes of the antiferromagnetic layer 31 and the ferromagnetic layer 30 are both preferentially oriented in the film surface direction.
[0032]
Since both the (111) planes of the antiferromagnetic layer 31 and the ferromagnetic layer 30 are preferentially oriented in a direction parallel to the film plane, they are perpendicular to the (111) plane [111]. Both directions are in the same c direction in the figure.
[0033]
On the other hand, in this exchange coupling film, among the directions of the crystal axes existing in the (111) plane, for example, the [110] direction faces the same a direction in the figure as both the antiferromagnetic layer 31 and the ferromagnetic layer 30. I understand that.
[0034]
The exchange coupling film having the crystal orientation as described above is likely to occur when the antiferromagnetic layer 31 and the ferromagnetic layer 30 are epitaxially grown at the film formation stage. When grown epitaxially, the crystal orientation of the antiferromagnetic layer 31 and the ferromagnetic layer 30 is not only the same crystal plane is preferentially oriented in a direction parallel to the film surface, but is not in a positional relationship parallel to the film surface. Even in other crystal planes, the antiferromagnetic layer 31 and the ferromagnetic layer 30 can easily maintain a parallel state.
[0035]
By having the crystal orientation described above, the arrangement of atoms constituting each layer can easily correspond to one-to-one at the interface between the antiferromagnetic layer 31 and the ferromagnetic layer 30. Therefore, when it has the said crystal orientation, it is thought that the antiferromagnetic layer 31 is restrained by the crystal structure of the ferromagnetic layer 30, and does not raise | generate an appropriate regular transformation, and an exchange coupling magnetic field will become small.
[0036]
As described above, in the present invention, the crystal planes in the direction parallel to the film planes of the antiferromagnetic layer and the ferromagnetic layer are preferentially oriented with the same equivalent plane, and exist within the crystal plane. At least a part of the crystal axes are directed in different directions in the antiferromagnetic layer and the ferromagnetic layer, and such crystal orientation is discriminated from the transmission electron diffraction image described below. Is possible.
[0037]
In the present invention, an antiferromagnetic layer and a ferromagnetic layer are formed in contact with each other, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is constant. In the exchange coupling membrane
The transmission electron beam diffraction images of the antiferromagnetic layer and the ferromagnetic layer obtained by making the electron beam incident in a direction parallel to the interface show diffraction spots corresponding to reciprocal lattice points representing the crystal planes of the respective layers. Appears,
Among the diffraction spots, the same indexing is made in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer, and the diffraction spots showing a certain crystal plane located in the film thickness direction when viewed from the beam origin, The first imaginary line connecting the beam origin coincides with the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer,
The second imaginary line connecting the diffraction origin showing the crystal plane and the beam origin, which is indexed in the same direction and located in a direction other than the film thickness direction when viewed from the origin of the beam, is antiferromagnetic The diffraction pattern of the layer and the diffraction pattern of the ferromagnetic layer are shifted from each other.
[0038]
In the present invention, the antiferromagnetic layer and the ferromagnetic layer are formed in contact with each other, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is constant. In the exchange coupling membrane,
In the transmission electron beam diffraction images of the antiferromagnetic layer and the ferromagnetic layer obtained by making an electron beam incident from a direction parallel to the interface, diffraction spots corresponding to reciprocal lattice points representing each crystal plane of each layer are obtained. Appear,
Among the diffraction spots, the same indexing is made in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer, and the diffraction spots showing a certain crystal plane located in the film thickness direction when viewed from the beam origin, The first imaginary line connecting the beam origin coincides with the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer,
When viewed from the beam origin, a diffraction spot indicating a crystal plane located in a direction other than the film thickness direction appears only in one of the diffraction images of the antiferromagnetic layer or the ferromagnetic layer, and To do.
[0039]
In the present invention, it is preferable that the diffraction spots located in the film thickness direction represent an equivalent crystal plane typically represented as a {111} plane.
[0040]
In the above invention, the crystal orientation of the antiferromagnetic layer and the ferromagnetic layer in the present invention is defined using a transmission electron beam diffraction image obtained by making an electron beam incident from a direction parallel to the interface.
[0041]
Here, the transmission electron beam diffraction image is an image showing a diffraction phenomenon caused by electron beam scattering (Bragg reflection) when an electron beam is incident on and transmitted through an object by a transmission electron microscope or the like.
[0042]
Based on the indexed diffraction pattern obtained from a general single crystal structure, indexing is performed on the diffraction spots appearing in the above diffraction image, thereby the crystal orientation of the antiferromagnetic layer and the ferromagnetic layer. Can be examined.
[0043]
As described above, in the present invention, of the diffraction spots, the same index is assigned to the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer, and a certain crystal located in the film thickness direction when viewed from the beam origin A first imaginary line connecting a diffraction spot indicating a surface and the beam origin coincides with each other in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. This means that the same crystal plane is preferentially oriented in the antiferromagnetic layer and the ferromagnetic layer in a direction parallel to the interface.
[0044]
Next, the second imaginary line connecting the beam origin and the diffraction spot showing a certain crystal plane, which is indexed and located in a direction other than the film thickness direction when viewed from the beam origin, The diffraction pattern of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer are shifted from each other. Alternatively, when viewed from the beam origin, diffraction spots indicating a crystal plane located in a direction other than the film thickness direction appear only in one of the diffraction images of the antiferromagnetic layer or the ferromagnetic layer. This is because the crystal plane located in a direction other than the direction parallel to the film plane is not in a parallel relationship between the antiferromagnetic layer and the ferromagnetic layer, and the crystal plane is shifted between the antiferromagnetic layer and the ferromagnetic layer. It has become.
[0045]
That is, in the present invention, the crystal planes of the antiferromagnetic layer and the ferromagnetic layer are preferentially oriented in the same equivalent crystal plane in the direction parallel to the interface, but the other crystal planes are the same as the antiferromagnetic layer and the ferromagnetic layer. It is presumed that the arrangement of atoms in the antiferromagnetic layer and the arrangement of atoms in the ferromagnetic layer are not in a one-to-one relationship at the interface.
[0046]
16 and 17 show transmission electron beam diffraction images obtained by cutting a laminated film (spin valve film) from the film thickness direction and allowing an electron beam to enter from a direction perpendicular to the cross section (that is, a direction parallel to the film surface). It is. The transmission electron beam diffraction image shown in FIG. 16 was obtained with an electron beam aperture such that both an antiferromagnetic layer and a layer other than the antiferromagnetic layer were irradiated with an electron beam at the same time. .
[0047]
18 is a schematic diagram of the transmission electron beam diffraction image shown in FIG. 16, and FIG. 19 is a schematic diagram of the transmission electron beam diffraction image shown in FIG.
[0048]
FIG. 16 is a transmission electron diffraction image measured from the spin valve film of the present invention having the following film structure.
Al₂O_Three(3 nm) / Ta (3 nm) / seed layer: Ni₈₀Fe₂₀(2 nm) / Antiferromagnetic layer: Pt₅₄Mn₄₆(15 nm) / pinned magnetic layer: [Co (1.5 nm / Ru (0.8 nm) / Co (2.5 nm)] / nonmagnetic intermediate layer: Cu (2.5 nm) / free magnetic layer: [Co (1 nm ) / Ni₈₀Fe₂₀(3 nm)] / backed layer: Cu (1.5 nm) / protective layer: Ta (1.5 nm) / Ta oxide film.
[0049]
FIG. 17 is a transmission electron beam diffraction image measured from a spin valve film of a comparative example having the following film configuration.
Al₂O_Three(3 nm) / Ta (3 nm) / seed layer: Ni₈₀Fe₂₀(2 nm) / Antiferromagnetic layer: Pt₄₄Mn₅₆(13 nm) / pinned magnetic layer: [Co (1.5 nm / Ru (0.8 nm) / Co (2.5 nm)] / nonmagnetic intermediate layer: Cu (2.5 nm) / free magnetic layer: [Co (1 nm ) / Ni₈₀Fe₂₀(3 nm)] / backed layer: Cu (1.5 nm) / protective layer: Ta (1.5 nm) / Ta oxide film.
[0050]
The numerical values in parentheses in the film configuration described above indicate the film thickness of each layer. Further, in the electron diffraction image shown in FIG. 16, in the notation of the crystal plane expressed by the Miller index, “−” (bar) is added on the numeral “1”, which is “−1”. It is (minus 1), and is written as “−1” in the specification.
[0051]
As shown in FIG. 16, in the transmission electron beam diffraction image of the example, it is understood that diffraction spots of the antiferromagnetic layer (PtMn) indexed with the (1-11) plane appear in the film thickness direction. Similarly, in the film thickness direction, a layer other than the antiferromagnetic layer indexed as (1-11) plane (shown on the electron diffraction image as fcc-Co / Cu / NiFe). It can be seen that diffraction spots appear.
[0052]
When the diffraction spots are represented on the schematic diagram shown in FIG. 18, the first imaginary line connecting the (1-11) plane in the diffraction image of the antiferromagnetic layer and the indexed diffraction spots to the origin of the beam; It can be seen that the (1-11) plane in the diffraction image of a layer other than the antiferromagnetic layer and the first imaginary line connecting the indexed diffraction spot to the origin of the beam coincide with each other.
[0053]
Further, as shown in FIG. 16, in the transmission electron beam diffraction image of the example, diffraction spots of the antiferromagnetic layer (PtMn) indexed with the (−111) plane appear in directions other than the film thickness direction. Recognize. Similarly, in a direction other than the film thickness direction, a layer other than the antiferromagnetic layer indexed with the (−111) plane (shown as fcc-Co / Cu / NiFe on the electron diffraction image). It can be seen that diffraction spots appear.
[0054]
However, as shown in FIG. 18, it can be seen that the second imaginary lines connecting the diffraction spots and the beam origin do not coincide with each other and are shifted.
[0055]
That is, it can be seen from the electron diffraction patterns in the examples that the same equivalent crystal plane represented as the {111} plane is preferentially oriented in the direction parallel to the film thickness in the antiferromagnetic layer and the ferromagnetic layer. However, the crystal plane other than the crystal plane oriented parallel to the film plane is not in a parallel relationship between the antiferromagnetic layer and the ferromagnetic layer.
[0056]
In the examples shown in FIGS. 16 and 18, (−111) diffraction spots of both the antiferromagnetic layer and the ferromagnetic layer, that is, diffraction spots existing in a direction other than the film thickness direction appear. When the crystal orientation of one layer is in an orientation that is further rotated about the film thickness direction, the (−111) diffraction spots of either layer may not appear in the diffraction image. Even in such a case, the crystal plane other than the crystal plane oriented in parallel with the film plane means that the antiferromagnetic layer and the ferromagnetic layer are not in a parallel relationship.
[0057]
On the other hand, as shown in FIG. 17, in the transmission electron beam diffraction image of the comparative example, it can be seen that diffraction spots on the {111} plane of the antiferromagnetic layer (PtMn) appear in the film thickness direction. Similarly, diffraction spots on the {111} plane of layers other than the antiferromagnetic layer (shown as fcc-Co / Cu / NiFe on the electron diffraction image) appear in the film thickness direction. I understand that.
[0058]
  The diffraction spots appearing in the transmission electron beam diffraction image shown in FIG. 17 are not expressed as equivalent crystal planes such as the (111) plane and the (11-1) plane, but are expressed to include all these equivalent crystal planes. The {111} plane is specified differently from the case of FIG.{111}This is because it is not necessary to refer to the diffraction spots (for example, (−111)) in the explanation.
[0059]
Further, as shown in FIG. 17, it can be seen that in the transmission electron beam diffraction image of the comparative example, diffraction spots on the {200} plane of the antiferromagnetic layer (PtMn) appear in directions other than the film thickness direction. Similarly, diffraction spots on the {200} plane of layers other than the antiferromagnetic layer (shown as fcc-Co / Cu / NiFe on the electron diffraction image) appear in directions other than the film thickness direction. I understand that.
[0060]
As can be seen from the schematic diagram shown in FIG. 19, in the transmission electron beam diffraction image of the comparative example, diffraction spots on the {111} plane of the antiferromagnetic layer and the ferromagnetic layer appear in the film thickness direction when viewed from the beam origin. The first imaginary line connecting the diffraction spots and the beam origin coincides with each other in the diffraction images of the antiferromagnetic layer and the ferromagnetic layer, and appears in a direction other than the film thickness direction when viewed from the beam origin { The second imaginary line connecting the diffraction spot of the 200} plane and the beam origin also coincides with each other in the diffraction images of the antiferromagnetic layer and the ferromagnetic layer.
[0061]
That is, in the comparative example, the antiferromagnetic layer and the ferromagnetic layer have a parallel relationship even in the crystal plane that appears in a direction other than the film surface direction, which is an epitaxial growth of the antiferromagnetic layer and the ferromagnetic layer. It is presumed that at the interface between the antiferromagnetic layer and the ferromagnetic layer, the arrangement of atoms in the antiferromagnetic layer and the arrangement of atoms in the ferromagnetic layer are in a one-to-one correspondence. It has become easier. And in the said matching state, the said antiferromagnetic layer cannot raise | generate an appropriate regular transformation by heat processing, and cannot exhibit a big exchange coupling magnetic field.
[0062]
When the exchange coupling magnetic field (Hex) of the spin valve film actually formed by the film structure of the comparative example was measured, it was 0.24 × 10^FourOnly an exchange coupling magnetic field as low as (A / m) was obtained.
[0063]
On the other hand, in the present invention, the same equivalent crystal plane is preferentially oriented in the direction parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer, but the antiferromagnetic layer and the strong layer are strong in other crystal planes. There is no parallel relationship with the magnetic layer. In other words, this is a state in which the crystal orientation of the antiferromagnetic layer and the ferromagnetic layer is rotated about the direction perpendicular to the interface, and in a crystal plane preferentially oriented in a direction parallel to the interface. This means that at least a part of the same equivalent crystal axis that exists is oriented in different directions on the antiferromagnetic layer side and the ferromagnetic layer side.
[0064]
Therefore, there is no one-to-one relationship between the arrangement of atoms in the antiferromagnetic layer and the arrangement of atoms in the ferromagnetic layer at the interface, and when the antiferromagnetic layer is subjected to heat treatment, the antiferromagnetic layer is strong. It is considered that an appropriate regular transformation is caused without being constrained by the crystal structure of the magnetic layer, and a larger exchange coupling magnetic field can be obtained compared to the conventional case.
[0065]
When the exchange coupling magnetic field (Hex) of the spin valve film of the present invention actually used in the above experiment was measured, it was 10.9 × 10^FourA very large exchange coupling magnetic field of (A / m) could be obtained.
[0066]
Further, according to the present invention, an antiferromagnetic layer and a ferromagnetic layer are formed in contact with each other, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is a constant direction. In the exchange coupling membrane,
In the transmission electron beam diffraction images of the antiferromagnetic layer and the ferromagnetic layer obtained by making the electron beam incident from the direction perpendicular to the interface, diffraction spots corresponding to reciprocal lattice points representing the crystal planes of the respective layers are obtained. Appear,
Among the diffraction spots, an imaginary line connecting the diffraction spot of the antiferromagnetic layer and the diffraction origin of the ferromagnetic layer and connecting from the diffraction spot to the beam origin is a diffraction image of the antiferromagnetic layer. And the diffraction pattern of the ferromagnetic layer are shifted from each other.
[0067]
  Alternatively, in the present invention, the antiferromagnetic layer and the ferromagnetic layer are formed in contact with each other, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is a constant direction. In the exchange coupling membrane,
  In the transmission electron beam diffraction images of the antiferromagnetic layer and the ferromagnetic layer obtained by making the electron beam incident from the direction perpendicular to the interface, diffraction spots corresponding to reciprocal lattice points representing the crystal planes of the respective layers are obtained. Appear,
  Among the diffraction spots, diffraction spots with an index appear only in one of the diffraction images of the antiferromagnetic layer or the ferromagnetic layer,
The crystal plane parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer is preferentially oriented to the same equivalent crystal plane, and at least a part of the same equivalent crystal axis existing in the crystal plane is the The antiferromagnetic layer and the ferromagnetic layer are facing different directions.It is characterized by this.
[0068]
In the present invention, the direction perpendicular to the interface is preferably an equivalent crystal axis direction represented as a <111> direction.
[0069]
In the present invention, the crystal plane parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer is preferably an equivalent crystal plane typically represented as a [111] plane.
[0070]
In this invention, the transmission electron beam diffraction image is measured from the direction perpendicular to the interface.
[0071]
In the transmission electron beam diffraction image of the antiferromagnetic layer and the transmission electron beam diffraction image of the ferromagnetic layer, diffraction spots corresponding to reciprocal lattice points representing the crystal planes of the respective layers appear.
[0072]
Further, among the diffraction spots, the imaginary line connecting the diffraction spot and the beam origin, which is indexed in the diffraction pattern of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer, is the diffraction pattern of the antiferromagnetic layer. The image and the diffraction image of the ferromagnetic layer are shifted from each other. Alternatively, a certain diffraction spot appears only on one diffraction image and does not appear on the other. This means that other crystal planes not located in the direction parallel to the interface are not in a parallel relationship between the antiferromagnetic layer and the ferromagnetic layer.
[0073]
That is, in the present invention, both the antiferromagnetic layer and the ferromagnetic layer are preferentially oriented in the same equivalent crystal plane in the film plane direction, but the other crystal plane not oriented in the film plane direction is the antiferromagnetic layer. There is no parallel relationship between the layer and the ferromagnetic layer, which is a state in which the crystal orientation of the antiferromagnetic layer and the ferromagnetic layer is rotated at an angle with the axis perpendicular to the interface as an axis. At the interface, it is considered that the arrangement of atoms in the antiferromagnetic layer does not correspond to the arrangement of atoms in the ferromagnetic layer on a one-to-one basis.
[0074]
20 to 22 conceptually show the above-mentioned transmission electron beam diffraction images. The transmission electron diffraction pattern shown in FIG. 20 is the electron diffraction pattern of the PtMn crystal, FIG. 21 is the electron diffraction pattern of the ferromagnetic layer (fcc-Co) crystal, and FIG. This is a figure in which the diffraction spots (beam origin) of (000) shown in FIG.
[0075]
In addition, the black circle shown in FIG. 20 is a diffraction spot, and the numerical value indexed to each diffraction spot is described. Similarly, white circles shown in FIG. 21 are diffraction spots, and numerical values indexed to the respective diffraction spots are described.
[0076]
As shown in FIG. 20, the crystal axis direction connecting the beam origin (000) and the diffraction spot (-2-24) indicates the [-1-12] direction. The crystal axis direction connecting the beam origin (000) and the diffraction spots (2-20) indicates the [1-10] direction.
[0077]
The diffraction pattern shown in FIG. 21 is indexed in the same manner as shown in FIG. 20, and the [-1-12] direction and [1-10] direction are shown. It can be seen that the direction is different from the corresponding crystal axis direction shown in FIG.
[0078]
That is, as can be seen from FIG. 22 in which the diffraction pattern shown in FIG. 20 and the diffraction pattern shown in FIG. 21 are superimposed, a hypothesis connecting the diffraction spot (-2-24) of the antiferromagnetic layer and the beam origin (000) is connected. The line {circle over (1)} is separated from the phantom line {circle around (2)} connecting the diffraction spot (−2−24) of the ferromagnetic layer and the beam origin (000), and the diffraction of the antiferromagnetic layer is similarly performed. An imaginary line (3) connecting the spot (2-20) and the beam origin (000) deviates from a virtual line (4) connecting the diffraction spot (2-20) of the ferromagnetic layer and the beam origin (000). It turns out that it is in the state.
[0079]
As can be seen from the transmission electron diffraction pattern described above, the antiferromagnetic layer and the ferromagnetic layer are the same in the direction parallel to the film surface, as in the crystal orientation of the present invention described with reference to FIG. Equivalent crystal planes are preferentially oriented, but the same equivalent crystal axis direction existing in the crystal plane faces different directions in the antiferromagnetic layer and the ferromagnetic layer, in other words In other crystal planes that are not oriented in the direction parallel to the film plane, the antiferromagnetic layer and the ferromagnetic layer are non-parallel.
[0080]
23 to 25 show the transmission electron diffraction patterns of the comparative example, FIG. 23 shows the transmission electron diffraction patterns of the antiferromagnetic layer (PtMn) crystal, and FIG. 24 shows the transmission of the ferromagnetic layer (fcc-Co) crystal. An electron diffraction pattern, FIG. 25, is a diffraction pattern in which the beam origins appearing in the diffraction patterns of FIGS.
[0081]
As shown in FIGS. 23 and 24, the crystal axis directions [-1-12] connecting the diffraction spots (-2-24) of the antiferromagnetic layer and the ferromagnetic layer and the beam origin point in the same direction. In addition, the crystal axis direction [1-10] direction connecting the diffraction spots (2-20) of the antiferromagnetic layer and the ferromagnetic layer and the beam origin point also in the same direction.
[0082]
That is, as shown in FIG. 25, the phantom line (5) connecting the diffraction spot (-2-24) and the beam origin coincides with each other between the diffraction pattern of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer. The phantom line (6) connecting the diffraction spot (2-20) to the origin is also coincident with each other between the diffraction pattern of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer.
[0083]
In the comparative example, in the antiferromagnetic layer and the ferromagnetic layer, not only the same equivalent crystal plane is preferentially oriented in the direction parallel to the film surface, but also the directions of the same equivalent crystal axes existing in the crystal plane are Are completely matched between the antiferromagnetic layer and the ferromagnetic layer, and the parallel relationship between the antiferromagnetic layer and the ferromagnetic layer also exists in other crystal planes that are not located in the direction parallel to the film surface. It means that it has.
[0084]
As described above, in the present invention, the transmission electron beam diffraction images shown in FIGS. 16 to 25 are used, and the difference that can be discriminated from the diffraction images of the spin valve film of the present invention and the spin valve film of the comparative example has been described. Transmission electron diffraction images as in the present invention show that the same equivalent crystal plane is preferentially oriented in the direction parallel to the film surface of the antiferromagnetic layer and the ferromagnetic layer, and exists in the same crystal plane. It can be proved that at least a part of the crystal axes are oriented in different directions in the antiferromagnetic layer and the ferromagnetic layer.
[0085]
The configuration of the present invention as described above is achieved when, for example, a seed layer described below is provided.
[0086]
  In the present invention, the exchange coupling film is laminated in the order of an antiferromagnetic layer and a ferromagnetic layer from the bottom, and below the antiferromagnetic layer, the crystal structure is mainly composed of face centered cubic crystals, and the interface In a direction parallel to{111}It is preferable that a seed layer in which a crystal plane equivalent to the plane is preferentially oriented is formed.
[0087]
  Thus, in the present invention, by providing the seed layer below the antiferromagnetic layer, the antiferromagnetic layer and the ferromagnetic layer are typically in a direction parallel to the film surface.{111}An equivalent crystal plane represented as a plane is preferentially oriented. Thus, by arranging the same crystal plane in a direction parallel to the film surface, it is possible to obtain a larger resistance change rate (ΔR / R) than in the prior art.
[0088]
In the present invention, the seed layer is formed of a NiFe alloy or a Ni—Fe—Y alloy (where Y is at least one selected from Cr, Rh, Ta, Hf, Nb, Zr, and Ti). It is preferable. In the present invention, the seed layer is preferably nonmagnetic at room temperature.
[0089]
In the present invention, it is preferable that an underlayer formed of at least one element selected from Ta, Hf, Nb, Zr, Ti, Mo, and W is formed under the seed layer.
[0090]
In the present invention, it is preferable that at least a part of the interface between the ferromagnetic layer and the seed layer is in an inconsistent state.
[0091]
The antiferromagnetic layer includes elements X and X '(wherein element X' is Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, and one or more of rare earth elements Element) and Mn. In this case, the antiferromagnetic material is an interstitial solid solution in which the element X ′ penetrates into the space between the spatial lattices composed of the elements X and Mn, or a crystal lattice composed of the elements X and Mn. It is preferable that a part of the lattice points is a substitutional solid solution substituted with the element X ′. As a result, the lattice constant of the antiferromagnetic layer can be increased, and an atomic arrangement that does not correspond to the atomic arrangement of the ferromagnetic layer at the interface with the ferromagnetic layer can be formed.
[0092]
Incidentally, another important point for obtaining an exchange coupling film having the above-described crystal orientation is the composition ratio of each constituent element constituting the antiferromagnetic layer.
[0093]
In order to obtain a large exchange coupling magnetic field, when an antiferromagnetic layer is formed, the antiferromagnetic layer and the ferromagnetic layer remain in an inconsistent state in at least a part of the interface, and the antiferromagnetic layer is subjected to heat treatment. It is necessary to cause an appropriate ordered transformation. However, whether such a mismatched state and the ordered transformation are appropriately caused or not depends largely on the composition ratio of the antiferromagnetic layer.
[0094]
In the present invention, the composition ratio (atomic%) of the element X or the element X + X ′ is preferably 45 (at%) or more and 60 (at%) or less. According to the experimental results to be described later, when the composition ratio of the element X or the element X + X ′ is within the above range, it is at least 1.58 × 10 8.^FourAn exchange coupling magnetic field of (A / m) or more can be obtained. More preferably, the composition ratio of the element X or the element X + X ′ is not less than 49 (at%) and not more than 56.5 (at%), whereby 7.9 × 10^FourAn exchange coupling magnetic field of (A / m) or more can be obtained.
[0095]
When the composition range is within the above range, the antiferromagnetic layer maintains an inconsistent state at the interface with the ferromagnetic layer, and the antiferromagnetic layer can cause an appropriate ordered transformation by heat treatment.
[0096]
In the state after the heat treatment, the antiferromagnetic layer and the ferromagnetic layer have the same equivalent crystal plane preferentially oriented in a direction parallel to the film plane, and at least a crystal axis existing in the crystal plane. Some of the antiferromagnetic layer and the ferromagnetic layer are oriented in different directions.
[0097]
In the present invention, it is preferable that at least a part of the interface between the antiferromagnetic layer and the ferromagnetic layer is in an inconsistent state after the heat treatment.
[0098]
  In the present invention, the exchange coupling film described above can be applied to various magnetoresistive elements.
  In the present invention, an antiferromagnetic layer is formed in contact with the antiferromagnetic layer, and the magnetization direction is fixed by an exchange anisotropic magnetic field with the antiferromagnetic layer.Ferromagnetic layerAnd saidFerromagnetic layerA free magnetic layer formed through a nonmagnetic intermediate layer and a magnetization direction of the free magnetic layerFerromagnetic layerIn a magnetoresistive element having a bias layer aligned in the direction intersecting with the magnetization direction of
  Formed in contact with the antiferromagnetic layer and the antiferromagnetic layerFerromagnetic layerAre formed by the exchange coupling film according to any one of claims 1 to 19.
[0099]
  In the present invention, an antiferromagnetic layer is formed in contact with the antiferromagnetic layer, and the magnetization direction is fixed by an exchange anisotropic magnetic field with the antiferromagnetic layer.Ferromagnetic layerAnd saidFerromagnetic layerIn which an antiferromagnetic exchange bias layer is formed on the upper or lower side of the free magnetic layer with an interval in the track width direction. In a resistance effect element,
  SaidAntiferromagnetic layerWhenFerromagnetic layerAre formed of the above-described exchange coupling film, and the magnetization of the free magnetic layer is in a certain direction.
[0100]
  Further, the present invention is located in a nonmagnetic intermediate layer stacked above and below a free magnetic layer, above one of the nonmagnetic intermediate layers and below the other nonmagnetic intermediate layer.FerromagneticLayer and one of the aboveFerromagnetic layerAbove and the otherFerromagneticEach layer is located under a layer by an exchange anisotropic magnetic fieldFerromagneticAn antiferromagnetic layer that fixes the magnetization direction of the layer in a fixed direction, and the magnetization direction of the free magnetic layerFerromagneticIn a magnetoresistive element having a bias layer aligned in a direction crossing the magnetization direction of the layer,
  Formed in contact with the antiferromagnetic layer and the antiferromagnetic layerFerromagneticThe layer is formed of the exchange coupling film described above.
[0101]
  Furthermore, the present invention has a magnetoresistive layer and a soft magnetic layer stacked via a nonmagnetic layer,The magnetoresistive layer is formed of a ferromagnetic layer;In the magnetoresistive element in which the antiferromagnetic layer is formed on the upper side or the lower side of the magnetoresistive layer with an interval in the track width direction,
  The antiferromagnetic layer and the magnetoresistive layer are formed of the exchange coupling film described above.
[0102]
The thin film magnetic head according to the present invention is characterized in that shield layers are formed above and below the magnetoresistive element via a gap layer.
[0103]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view of the entire structure of a single spin-valve magnetoresistive effect element according to the first embodiment of the present invention as viewed from the ABS side. In FIG. 1, only the central portion of the element extending in the X direction is shown broken away.
[0104]
This single spin-valve magnetoresistive element is provided at the trailing end of a floating slider provided in a hard disk device and detects a recording magnetic field of a hard disk or the like. The moving direction of a magnetic recording medium such as a hard disk is the Z direction, and the direction of the leakage magnetic field from the magnetic recording medium is the Y direction.
[0105]
The lowermost layer in FIG. 1 is an underlayer 6 formed of a nonmagnetic material such as one or more elements of Ta, Hf, Nb, Zr, Ti, Mo, and W. The underlayer 6 is provided for preferentially orienting an equivalent crystal plane represented as a {111} plane of the seed layer 22 formed thereon in a direction parallel to the film plane. The underlayer 6 is formed with a film thickness of about 50 mm, for example.
[0106]
The seed layer 22 is mainly composed of face-centered cubic crystals, and an equivalent crystal plane typically represented as a {111} plane is preferentially oriented in a direction parallel to the interface with the antiferromagnetic layer 4. . The seed layer 22 is formed of a NiFe alloy or a Ni—Fe—Y alloy (where Y is at least one selected from Cr, Rh, Ta, Hf, Nb, Zr, and Ti). Is preferred.
[0107]
  Here, the “equivalent crystal plane” means a crystal lattice plane expressed using a Miller index,{111}Equivalent (equivalent) crystal planes expressed as planes include (111) plane, (−111) plane, (1-11) plane, (11-1) plane, (−1-11) plane, (1- There are a 1-1) plane, a (-11-1) plane, and a (-1-1-1) plane.
[0108]
That is, in the present invention, the seed layer 22 is preferentially oriented in the direction parallel to the film surface such as the (111) plane or the equivalent (1-11) plane.
[0109]
In the present invention, the seed layer 22 is preferably nonmagnetic at room temperature. By making the seed layer 22 non-magnetic at room temperature, it is possible to prevent deterioration of waveform asymmetry (asymmetry), and the effect of the element Y added to make it non-magnetic (described later) makes the seed layer 22 non-magnetic. 22 can be increased, and the shunting of the sense current flowing from the conductive layer to the seed layer 22 can be suppressed. If the sense current is easily diverted to the seed layer 22, it is not preferable because it leads to a decrease in the rate of change in resistance (ΔR / R) and generation of Barkhausen noise.
[0110]
  In order to form the seed layer 22 non-magnetically, a Ni—Fe—Y alloy (where Y is selected from Cr, Rh, Ta, Hf, Nb, Zr, and Ti among the above materials) More than species) can be selected. These materials typically have a face-centered cubic crystal structure and are typically in a direction parallel to the film surface.{An equivalent crystal plane represented as a 111} plane is preferred because it is preferentially oriented. The seed layer 22 is formed with, for example, about 30 mm.
[0111]
An antiferromagnetic layer 4 is formed on the seed layer 22. The antiferromagnetic layer 4 is an antiferromagnetic material containing the element X (where X is one or more of Pt, Pd, Ir, Rh, Ru, and Os) and Mn. Preferably it is formed.
[0112]
X-Mn alloys using these platinum group elements have excellent properties as antiferromagnetic materials, such as excellent corrosion resistance, high blocking temperature, and an increased exchange coupling magnetic field (Hex). It is particularly preferable to use Pt among platinum group elements. For example, a PtMn alloy formed by a binary system can be used.
[0113]
In the present invention, the antiferromagnetic layer 4 is composed of the element X and the element X ′ (where the element X ′ is Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti). , V, Cr, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, and rare earth elements Alternatively, it may be formed of an antiferromagnetic material containing Mn and two or more elements.
[0114]
In addition, as the element X ′, an element that penetrates into the space between the spatial lattices composed of the elements X and Mn or replaces part of the lattice points of the crystal lattice composed of the elements X and Mn is used. Is preferred. Here, the solid solution refers to a solid in which components are uniformly mixed in one crystal phase.
[0115]
By using the interstitial solid solution or the substitutional solid solution, the lattice constant of the X-Mn-X 'alloy can be made larger than the lattice constant of the X-Mn alloy film. And the interface structure between the antiferromagnetic layer 4 and the pinned magnetic layer 3 can be easily brought into a mismatched state. In particular, when the element X ′ that is a solid solution in substitutional form is used, if the composition ratio of the element X ′ is too large, the antiferromagnetic characteristics are deteriorated and generated at the interface with the pinned magnetic layer 3. The exchange coupling magnetic field becomes small. In particular, in the present invention, it is preferable to use an inert gas rare gas element (one or more of Ne, Ar, Kr, and Xe) as the element X ′, which is an intrusive solid solution. Since the rare gas element is an inert gas, even if the rare gas element is contained in the film, the antiferromagnetic properties are not greatly affected. Further, Ar or the like has been conventionally used as a sputtering gas in the sputtering apparatus. Ar gas can be easily introduced by simply adjusting the gas pressure appropriately.
[0116]
When a gas-based element is used as the element X ′, it is difficult to contain a large amount of the element X ′ in the film. However, in the case of a rare gas, it is only necessary to enter a small amount into the film. The exchange coupling magnetic field generated by the heat treatment can be greatly increased.
[0117]
In the present invention, the composition range of the element X ′ is preferably 0.2 to 10 in at%, and more preferably 0.5 to 5 in at%. In the present invention, the element X is preferably Pt. Therefore, it is preferable to use a Pt—Mn—X ′ alloy.
[0118]
Next, the pinned magnetic layer 3 formed of a three-layer film is formed on the antiferromagnetic layer 4.
[0119]
The pinned magnetic layer 3 is formed of a Co film 11, a Ru film 12, and a Co film 13, and the magnetization direction of the Co film 11 and the Co film 13 is changed by an exchange coupling magnetic field at the interface with the antiferromagnetic layer 4. They are antiparallel to each other. This is referred to as a so-called ferrimagnetic coupling state, and this configuration can stabilize the magnetization of the pinned magnetic layer 3 and can generate an exchange coupling magnetic field generated at the interface between the pinned magnetic layer 3 and the antiferromagnetic layer 4. Can be bigger.
[0120]
For example, the Co film 11 is formed with a thickness of about 20 mm, the Ru film 12 is formed with a thickness of about 8 mm, and the Co film 13 is formed with a thickness of about 15 mm.
[0121]
The pinned magnetic layer 3 may not be formed of a three-layer film, for example, a single-layer film. The layers 11, 12, and 13 may be formed of a material other than the magnetic material described above.
[0122]
A nonmagnetic intermediate layer 2 is formed on the pinned magnetic layer 3. The nonmagnetic intermediate layer 2 is made of Cu, for example. In the case where the magnetoresistive effect element in the present invention is a tunnel type magnetoresistive effect element (TMR element) using the principle of the tunnel effect, the nonmagnetic intermediate layer 2 is made of, for example, Al.₂O_ThreeEtc. are formed of an insulating material.
[0123]
Further, a free magnetic layer 1 formed of a two-layer film is formed on the nonmagnetic intermediate layer 2.
[0124]
The free magnetic layer 1 is formed of two layers of a NiFe alloy film 9 and a Co film 10. As shown in FIG. 1, the Co film 10 is formed on the side in contact with the nonmagnetic intermediate layer 2 to prevent diffusion of a metal element or the like at the interface with the nonmagnetic intermediate layer 2, and ΔR / R (resistance (Change rate) can be increased.
[0125]
The NiFe alloy film 9 is formed, for example, with the Ni being 80 (at%) and the Fe being 20 (at%). Further, the NiFe alloy film 9 is formed with a film thickness of about 45 mm and a Co film of about 5 mm, for example.
[0126]
As shown in FIG. 1, a protective layer 7 made of a nonmagnetic material such as one or more elements of Ta, Hf, Nb, Zr, Ti, Mo, and W is formed on the free magnetic layer 1. Is formed.
[0127]
Further, a hard bias layer 5 and a conductive layer 8 are formed on both sides of the laminated film from the base layer 6 to the protective layer 7. The magnetization of the free magnetic layer 1 is aligned in the track width direction (X direction in the drawing) by the bias magnetic field from the hard bias layer 5.
[0128]
The hard bias layers 5 and 5 are made of, for example, a Co—Pt (cobalt-platinum) alloy or a Co—Cr—Pt (cobalt-chromium-platinum) alloy, and the conductive layers 8 and 8 are made of α-Ta. , Au, Cr, Cu (copper), W (tungsten) and the like. In the case of the tunnel type magnetoresistive effect element described above, the conductive layers 8 are formed below the free magnetic layer 1 and above the antiferromagnetic layer 4, respectively.
[0129]
In the present invention, a backed layer made of a metal material or a nonmagnetic metal such as Cu, Au, or Ag may be formed on the above-described free magnetic layer 1. For example, the backed layer is formed with a thickness of about 12 to 20 mm.
[0130]
The protective layer 7 is preferably formed with an oxide layer made of Ta or the like and having its surface oxidized.
[0131]
By forming the backed layer, the mean free path in electrons of + spin (up spin) contributing to the magnetoresistive effect is extended, and the spin filter effect (spin filter effect) is used to increase the spin. In the valve-type magnetic element, a large resistance change rate can be obtained, and the recording density can be increased.
[0132]
After laminating the above layers, in the present invention, a heat treatment is performed to generate an exchange coupling magnetic field (Hex) at the interface between the antiferromagnetic layer 4 and the pinned magnetic layer 3, thereby increasing the magnetization of the pinned magnetic layer 3. The spin valve thin film element after heat treatment has the following crystal orientation, although fixed in the direction (Y direction in the figure).
[0133]
The crystal orientation will be described mainly with respect to an exchange coupling film formed of an antiferromagnetic layer and a ferromagnetic layer (pinned magnetic layer).
[0134]
  In the present invention, as described above, the seed layer 22 is formed below the antiferromagnetic layer 4. The seed layer 22 is typically{111}The equivalent crystal plane represented as a plane is formed so as to be preferentially oriented in the film plane, whereby the antiferromagnetic layer 4 formed on the seed layer 22 is also in a direction parallel to the film plane, The same crystal plane as the seed layer 22 is preferentially oriented in a direction parallel to the film plane.
[0135]
For example, when the (−111) plane is preferentially oriented in the direction parallel to the film surface, the antiferromagnetic layer 4 formed on the seed layer 22 is also (−111) in the direction parallel to the film surface. The plane is preferentially oriented.
[0136]
Furthermore, the pinned magnetic layer 3 formed on the antiferromagnetic layer 4 also has the same crystal plane as that of the antiferromagnetic layer 4 preferentially oriented in a direction parallel to the film surface.
[0137]
In other words, in the present invention, the seed layer 22, the antiferromagnetic layer 4 and the pinned magnetic layer 3 are preferentially oriented in the same parallel crystal plane, typically represented as {111} plane, in a direction parallel to the film plane. It is.
[0138]
  In the present invention, the crystal plane preferentially oriented in the direction parallel to the film plane is typically{111}The crystal plane is preferably an equivalent crystal plane expressed as a plane because the crystal plane is the closest packed plane. For example, when the environmental temperature and the sense current density in the magnetic head device are increased, thermal stability is particularly required, but the closest surface is parallel to the film surface.{111}When the equivalent crystal plane expressed as a plane is preferentially oriented, it is difficult for atoms to diffuse in the film thickness direction, the thermal stability of the multilayer film interface is increased, and the characteristics can be stabilized.
[0139]
In the present invention, the antiferromagnetic layer 4 and the pinned magnetic layer 3 are thus preferentially oriented in the same crystal plane in a direction parallel to the film surface. In the present invention, however, the same crystal exists in the crystal plane. At least a part of the axis faces different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3 (see FIG. 14). In FIG. 14, it can be seen that, for example, the [110] direction existing in the (111) plane faces different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0140]
The cause of such crystal orientation is considered to depend on the state in which the antiferromagnetic layer 4 and the pinned magnetic layer 3 are formed in the film formation stage (before heat treatment).
[0141]
For example, when the material and composition ratio of the antiferromagnetic layer 4 are adjusted and each layer is formed in a state where the lattice constant of the antiferromagnetic layer 4 is sufficiently larger than the lattice constant of the pinned magnetic layer 3, the antiferromagnetic layer 4 is formed. It is considered that the layer 4 and the pinned magnetic layer 3 are difficult to grow epitaxially.
[0142]
When the film is formed epitaxially, the antiferromagnetic layer 4 and the pinned magnetic layer 3 are easily formed with all crystal orientations in a parallel relationship. At the interface between the antiferromagnetic layer 4 and the pinned magnetic layer 3, not only the same crystal plane is preferentially oriented in a direction parallel to the interface, but also the antiferromagnetic layer 4 and the pinned layer existing in the crystal plane. The same crystal axis with the magnetic layer 3 is directed in the same direction, and the arrangement of atoms in the antiferromagnetic layer 4 and the arrangement of atoms in the pinned magnetic layer 3 are likely to correspond one-to-one at the interface (FIG. 15). reference). As a specific example, FIG. 15 shows that the [110] direction existing in the (111) plane faces the same direction in the antiferromagnetic layer 31 and the ferromagnetic layer 30.
[0143]
If such crystal orientation occurs in the stage before the heat treatment, the antiferromagnetic layer 4 is restricted by the crystal structure of the pinned magnetic layer 3 even if the heat treatment is performed, and does not cause an appropriate regular transformation. The coupling field is greatly reduced.
[0144]
In the present invention, it is considered that the antiferromagnetic layer 4 and the pinned magnetic layer 3 are formed without epitaxial growth as described above. When heat treatment is performed in such a film formation state, The antiferromagnetic layer 4 is not restricted by the crystal structure of the pinned magnetic layer 3 and causes appropriate regular transformation. When the film structure of the spin valve film in the present invention after the heat treatment is observed, the antiferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane in the direction parallel to the film plane, In other crystal planes that are not oriented in the direction parallel to the film plane, the antiferromagnetic layer 4 and the pinned magnetic layer 3 do not maintain a parallel relationship, and as a result, the crystal plane is oriented in parallel to the film plane. At least some of the same equivalent crystal axes that exist exist in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0145]
In the present invention, the seed layer 22 is laid under the antiferromagnetic layer 4 as one method for generating the above crystal orientation. As already described, by providing the seed layer 22, the anti-ferromagnetic layer 4 and the pinned magnetic layer 3 formed on the seed layer 22 are preferentially oriented in the same equivalent crystal plane in the direction parallel to the film surface, Such crystal orientation results in a large resistance change rate (ΔR / R).
[0146]
In the present invention, at least some of the same equivalent crystal axes existing in the crystal planes oriented in the direction parallel to the film surfaces of the antiferromagnetic layer 4 and the pinned magnetic layer 3 are directed in different directions. However, the existence of such a crystal orientation is that the antiferromagnetic layer 4 is not restricted by the crystal structure of the pinned magnetic layer 3 in the heat treatment stage, but from the face-centered cubic lattice as the disordered phase to CuAu as the ordered phase. It is considered that the surface has been appropriately transformed into a -I type face-centered square lattice, and a large exchange coupling magnetic field can be obtained as compared with the conventional case. In the present invention, it is only necessary that at least a part of the crystal structure of the antiferromagnetic layer 4 is a CuAu-I type face centered tetragonal lattice after the heat treatment.
[0147]
Further, whether or not it has the above crystal orientation can be determined by cutting the antiferromagnetic layer 4 and the pinned magnetic layer 3 from the film thickness direction (Z direction in the drawing) and viewing the crystal structure at the cut surface. Is possible.
[0148]
That is, in the present invention, the crystal grain boundary of the antiferromagnetic layer 4 appearing on the cut surface and the crystal grain boundary of the pinned magnetic layer 3 are at least one of the interfaces between the antiferromagnetic layer 4 and the pinned magnetic layer 3. It is in a discontinuous state at the part.
[0149]
As shown in FIGS. 26 and 28 (FIG. 26 is a transmission electron micrograph (TEM photograph) and FIG. 28 is a schematic diagram of the photograph shown in FIG. 26), in the present invention, the PtMn alloy film (antiferromagnetic layer 4) is formed. The crystal grain boundaries (4) (5) and the crystal grain boundaries (1) (2) (3) formed in the upper layer of the antiferromagnetic layer 4 are discontinuous at the interface, When such a discontinuous state occurs, a certain equivalent crystal existing on the crystal plane in the film plane direction of the antiferromagnetic layer 4 and the crystal plane in the film plane direction of the pinned magnetic layer 3 at the interface. It can be inferred that at least a part of the axis faces a different direction.
[0150]
The crystal structure shown in FIGS. 26 and 28 is the same as the crystal structure shown in FIGS. 27 and 29 (FIG. 27 is a transmission electron micrograph (TEM photograph) and FIG. 29 is a schematic diagram of the photograph shown in FIG. 27). Is clearly different. 27 and 29, the crystal grain boundary formed in the PtMn alloy film (antiferromagnetic layer 4) and the crystal grain boundary formed in the layer above the PtMn alloy film are continuous at the interface, and the antiferromagnetic layer 4 This is because large crystal grains penetrating the interface are formed from the upper layer to the upper layer.
[0151]
In the case of an exchange coupling film having a grain boundary as shown in FIGS. 26 and 28 as in the present invention, the antiferromagnetic layer 4 and the pinned magnetic layer 3 do not grow epitaxially in the film formation stage. Therefore, the antiferromagnetic layer 4 is appropriately restrained by heat treatment without being constrained by the crystal structure of the pinned magnetic layer 3, and a large exchange coupling magnetic field can be obtained. It is.
[0152]
In the present invention, after the antiferromagnetic layer 4 and the pinned magnetic layer 3 are formed and heat-treated, the crystal orientation of the antiferromagnetic layer 4 and the pinned magnetic layer 3 is determined by a transmission electron diffraction image. When observed and this transmission electron diffraction image is obtained as a diffraction pattern as described below, the crystal orientation of the antiferromagnetic layer 4 and the pinned magnetic layer 3 is the same as that of the antiferromagnetic layer 4 and the pinned magnetic layer. The same equivalent crystal plane is preferentially oriented in the direction parallel to the interface with 3 and at least a part of the same equivalent crystal axis existing in the crystal plane is the antiferromagnetic layer 4 and the pinned magnetic layer 3. It can be estimated that they are facing in different directions.
[0153]
In the present invention, an electron beam (beam) is first incident from a direction parallel to the interface between the antiferromagnetic layer 4 and the pinned magnetic layer 3, and a transmission electron beam diffraction image is obtained for each of the antiferromagnetic layer 4 and the pinned magnetic layer 3. obtain.
[0154]
In transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3, diffraction spots corresponding to reciprocal lattice points corresponding to the crystal planes of the respective layers appear. The reciprocal lattice point (= diffraction spot) is a crystal plane represented by a Miller index. For example, the reciprocal lattice point is a (110) plane.
[0155]
Next, indexing is performed on the diffraction spots. Since the distance r from the beam origin to the diffraction spot is inversely proportional to the lattice spacing d, d can be known by measuring r. Since the plane spacing of each crystal lattice plane {hkl} such as PtMn, CoFe, NiFe, etc. is known to some extent, an indexing of {hkl} equivalent to each diffraction spot can be made. Further, in the literature of general transmission electron beam diffraction images, transmissions in which a specific index of {hkl} is given to each diffraction spot, which is observed or calculated in various directions of crystal grains having a single crystal structure. The electron diffraction pattern is published. Using such a document, the diffraction spots obtained from the transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3 are the same as the diffraction spots of which crystal plane in the case of a single crystal structure or It is discriminated whether they are similar to each other, and indexing {hkl} similar to the case of the single crystal is performed for each individual diffraction spot.
[0156]
Then, the beam origins appearing in the transmission electron beam diffraction image of the antiferromagnetic layer 4 and the transmission electron beam diffraction image of the pinned magnetic layer 3 are made to coincide with each other and the diffraction images are superimposed.
[0157]
Alternatively, a transmission electron beam diffraction image is obtained within a range in which both the diamagnetic layer 4 and the pinned magnetic layer 3 are simultaneously irradiated with electron beams.
[0158]
In the present invention, among the diffraction spots, the same index is applied to the diffraction image of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3, and a certain crystal plane located in the film thickness direction when viewed from the beam origin The first imaginary line connecting the diffraction spots indicating the beam origin and the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer coincide with each other (see FIGS. 16 and 18; FIG. 16 is transmitted). Electron diffraction image, FIG. 18 is a schematic diagram of the diffraction image shown in FIG. This means that the equivalent crystal planes of the antiferromagnetic layer 4 and the pinned magnetic layer 3 are preferentially oriented in the film surface direction.
[0159]
Further, in the present invention, a second imaginary line connecting the beam origin and the diffraction spot indicating a certain crystal plane, which is positioned in a direction other than the film thickness direction when viewed from the beam origin, with the same indexing. Are shifted from each other in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer (see FIGS. 16 and 18). This means that the crystal planes that are not oriented in the direction parallel to the film plane are not parallel to each other in the antiferromagnetic layer 4 and the pinned magnetic layer 3. Alternatively, even when a diffraction spot indicating a crystal plane located in a direction other than the film thickness direction when viewed from the beam origin appears in only one diffraction image of the antiferromagnetic layer or the ferromagnetic layer, The magnetic layer 4 and the pinned magnetic layer 3 are not parallel to each other.
[0160]
In the present invention, a diffraction image clearly different from the comparative example shown in FIGS. 17 and 19 (FIG. 17 is a transmission electron diffraction image and FIG. 19 is a schematic diagram of the diffraction image shown in FIG. 17) can be obtained. In the comparative examples shown in FIGS. 17 and 19, the same indexing is performed, and diffraction spots showing a crystal plane located in a direction other than the film thickness direction when viewed from the beam origin are connected to the beam origin. This is because the second imaginary lines coincide with each other in the diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0161]
In the present invention, when a transmission electron beam diffraction image as shown in FIG. 16 is obtained, the same equivalent crystal plane is preferentially oriented in the direction parallel to the film surface of the antiferromagnetic layer 4 and the pinned magnetic layer 3, It can be presumed that at least a part of the same equivalent crystal axis existing in the crystal plane is oriented in different directions between the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0162]
Therefore, if the spin valve film can obtain the transmission electron beam diffraction image, the antiferromagnetic layer 4 has undergone appropriate regular transformation at the stage of heat treatment, and a large exchange coupling magnetic field can be obtained. is there.
[0163]
In the present invention, it is preferable that the diffraction spots located in the film thickness direction represent an equivalent crystal plane typically represented as a {111} plane.
[0164]
In the present invention, the crystal orientation of the antiferromagnetic layer 4 and the pinned magnetic layer 3 is observed by a transmission electron diffraction image from a direction different from the above, and the transmission electron diffraction image is described below. If obtained as a diffraction pattern, the antiferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film plane, and exist in the crystal plane. It can be presumed that at least a part of the crystal axes are directed in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0165]
That is, in the present invention, an electron beam (beam) is incident from the direction perpendicular to the interface between the antiferromagnetic layer 4 and the pinned magnetic layer 3, and a transmission electron beam diffraction image is simultaneously obtained for each of the antiferromagnetic layer 4 and the pinned magnetic layer 3. (See FIGS. 20 and 21; FIG. 20 is a schematic diagram of a diffraction image of the antiferromagnetic layer 4, and FIG. 21 is a schematic diagram of a diffraction image of the pinned magnetic layer 3).
[0166]
  In the transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3, diffraction spots of the same reciprocal lattice plane appear. The reciprocal lattice plane, that is, the projection plane of the electron diffraction pattern, is parallel to the crystal plane perpendicular to the incident electron beam. For example, the crystal plane parallel to the reciprocal lattice plane is the (111) plane. In the present invention, the direction perpendicular to the interface is the direction of an equivalent crystal axis typically represented as the <111> direction, or the crystal plane parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer. Is typically{111}It is preferably an equivalent crystal plane expressed as a plane.
[0167]
Next, the diffraction spots are indexed with reference to literatures of transmission electron beam diffraction images in the case of a single crystal structure. The antiferromagnetic layer 4 and the pinned magnetic layer 3 have a difference in lattice constant, that is, a difference in lattice spacing, so that the transmission electron beam diffraction spots of the antiferromagnetic layer 4 and the transmission electron beam diffraction spots of the pinned magnetic layer 3 Can be easily discriminated by the difference in distance between the spots and the beam origin (see FIG. 22).
[0168]
In the present invention, among the diffraction spots, the diffracted image of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3 are indexed in the same way. Line (1) and virtual line (2), and virtual line (3) and virtual line (4)) are shifted from each other in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. (See FIG. 22). This is because the orientation of a certain equivalent crystal axis existing in a crystal plane oriented in a direction parallel to the film surface is directed in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3. means. Alternatively, even in a state where a certain indexed diffraction spot among the diffraction spots appears only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer, the antiferromagnetic layer 4 and the pinned magnetic layer 3 have different directions. Means that you are facing.
[0169]
23 to 25 (FIG. 23 is a schematic diagram of a diffraction image of an antiferromagnetic layer, FIG. 24 is a schematic diagram of a diffraction image of a pinned magnetic layer, and FIG. 25 is a diagram of FIG. It can be seen that the transmission electron diffraction image of the comparative example shown in FIG.
[0170]
As shown in FIG. 25, the imaginary line (5) (6) connecting from a certain diffraction spot to the beam origin coincides with the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. is there.
[0171]
In the present invention, when the transmission electron beam diffraction images shown in FIGS. 20 to 22 are obtained, the anti-ferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane in the direction parallel to the film surface. However, it is presumed that at least a part of the same equivalent crystal axis existing in the crystal plane is oriented in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0172]
Therefore, if the spin valve film can obtain the transmission electron beam diffraction image, the antiferromagnetic layer 4 has undergone appropriate regular transformation at the stage of heat treatment, and a large exchange coupling magnetic field can be obtained. is there.
[0173]
As described above, the crystal orientation of the spin-valve type thin film element in the present invention and the feature points of the crystal grain boundary have been described. In order to obtain such crystal orientation and crystal grain boundary, the antiferromagnetic layer 4 and When the pinned magnetic layer 3 is formed, the antiferromagnetic layer 4 and the pinned magnetic layer 3 must be in a so-called inconsistent state at the interface.
[0174]
The non-matching state refers to a state where the arrangement of atoms in the antiferromagnetic layer 4 and the arrangement of atoms in the pinned magnetic layer 3 do not correspond one-to-one at the interface. It is necessary to expand the lattice constant of the antiferromagnetic layer 4 in comparison with the lattice constant of the pinned magnetic layer 3.
[0175]
In addition, the antiferromagnetic layer 4 must undergo appropriate ordered transformation by heat treatment. If the antiferromagnetic layer 4 does not cause a regular transformation even if the interface with the pinned magnetic layer 3 is in an inconsistent state, the exchange coupling magnetic field is eventually lowered.
[0176]
It is considered that the above-described inconsistency in the film formation stage and the appropriateness of whether or not to cause a regular transformation largely depend on the composition ratio of each constituent element constituting the antiferromagnetic layer 4.
[0177]
In the present invention, the atomic% of the element X or the element X + X ′ of the antiferromagnetic layer 4 is preferably set to 45 (at%) or more and 60 (at%) or less. As a result, it is presumed that the interface with the pinned magnetic layer 3 is brought into an inconsistent state in the film formation stage, and that the antiferromagnetic layer 4 undergoes an appropriate ordered transformation by heat treatment.
[0178]
By using the antiferromagnetic layer 4 formed within the above composition range, in the spin valve thin film element after the heat treatment, the crystal orientation of the antiferromagnetic layer 4 and the pinned magnetic layer 3 is changed to the film surface. In which the same equivalent crystal plane is preferentially oriented in a direction parallel to each other, and at least some of the same equivalent crystal axes existing in the crystal plane of the antiferromagnetic layer 4 and the pinned magnetic layer 3 are different from each other. It is possible to go to. The crystal grain boundary of the antiferromagnetic layer 4 and the crystal grain boundary of the pinned magnetic layer 3 can be made discontinuous at least at a part of the interface. According to the experimental results described later as being within the above composition range, 1.58 × 10^FourAn exchange coupling magnetic field of (A / m) or more can be obtained.
[0179]
In the present invention, the atomic% of the element X or the element X + X ′ is preferably set to 49 (at%) or more and 56.5 (at%) or less. As a result, 7.9 × 10^FourAn exchange coupling magnetic field of (A / m) or more can be obtained.
[0180]
In the present invention, in the spin valve thin film element having the above-described crystal orientation, at least a part of the interface between the antiferromagnetic layer 4 and the pinned magnetic layer 3 can be brought into a non-aligned state after the heat treatment. is there.
[0181]
The crystal orientation of the antiferromagnetic layer 4 and the pinned magnetic layer 3 and the transmission electron beam diffraction image are also observed between the seed layer 22 and the antiferromagnetic layer 4. That is, between the seed layer 22 and the antiferromagnetic layer 4, the same equivalent crystal plane is preferentially oriented in a direction parallel to the film surface, and at least of the same equivalent crystal axis existing in the crystal plane. Some of the seed layer 22 and the antiferromagnetic layer 4 face different directions.
[0182]
In addition, at least a part of the crystal grain boundary of the seed layer 22 and the crystal grain boundary of the antiferromagnetic layer 4 are discontinuous in a cross section in a direction parallel to the film thickness direction.
[0183]
When such crystal orientation and grain boundaries exist between the seed layer 22 and the antiferromagnetic layer 4, at least a part of the interface between the seed layer 22 and the antiferromagnetic layer 4 tends to be kept in an inconsistent state. Therefore, the antiferromagnetic layer 4 undergoes an appropriate regular transformation without being constrained by the crystal structure of the seed layer 22, and a larger exchange coupling magnetic field can be obtained.
[0184]
In the present invention, the antiferromagnetic layer 4 is preferably formed to have a thickness of 7 nm to 30 nm. Thus, in the present invention, an appropriate exchange coupling magnetic field can be generated even if the antiferromagnetic layer 4 is thin.
[0185]
FIG. 2 is a partial cross-sectional view showing the structure of another spin-valve type thin film element.
In this spin-valve type thin film element, from the bottom, the under layer 6, the free magnetic layer 1 composed of the NiFe alloy film 9 and the Co film 10, the nonmagnetic intermediate layer 2, the Co film 11, the Ru film 12, and the Co film 13 are used. A pinned magnetic layer 3, an antiferromagnetic layer 4 and a protective layer 7 are laminated. Hard bias layers 5 and 5 and conductive layers 8 and 8 are formed on both sides of the laminated film.
[0186]
The material of each layer is the same as that of the spin valve thin film element described in FIG.
[0187]
In the spin-valve type thin film element shown in FIG. 2, the antiferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film surface, and exist in the crystal plane. At least a part of the crystal axis is directed in different directions between the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0188]
Further, when the antiferromagnetic layer 4 and the pinned magnetic layer 3 are viewed in a cross section from a direction parallel to the film thickness (Z direction in the drawing), the crystal grain boundaries of the antiferromagnetic layer 4 and the crystals of the pinned magnetic layer 3 are observed. The grain boundary is in a discontinuous state at least at a part of the interface.
[0189]
For this reason, at least a part of the interface is kept in an inconsistent state, and the antiferromagnetic layer 4 has been subjected to appropriate regular transformation by heat treatment, so that a large exchange coupling magnetic field can be obtained.
[0190]
  The antiferromagnetic layer 4 and the pinned magnetic layer 3 are typically in a direction parallel to the film surface.{111}It is preferable that an equivalent crystal plane represented as a plane is preferentially oriented. In the crystal plane, it is preferable that the directions of equivalent crystal axes, which are typically expressed as <110> directions, are different from each other in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0191]
In the spin valve thin film element shown in FIG. 2, the transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3 obtained by making an electron beam (beam) incident from a direction parallel to the interface are respectively A diffraction spot corresponding to a reciprocal lattice point representing each crystal plane of the layer of the magnetic layer appears, and the diffraction index of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3 are indexed in the same manner and the beam out of the diffraction spots. A first imaginary line connecting a diffraction spot showing a certain crystal plane located in the film thickness direction when viewed from the origin and the beam origin is a diffraction image of the antiferromagnetic layer and a diffraction image of the ferromagnetic layer. Are consistent with each other.
[0192]
In addition, in the present invention, the second imaginary line connecting the origin and the diffraction spot indicating a certain crystal plane, which is assigned the same indexing and is located in a direction other than the film thickness direction when viewed from the beam origin, The diffraction pattern of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer are shifted from each other. Alternatively, when viewed from the beam origin, diffraction spots indicating a crystal plane located in a direction other than the film thickness direction appear only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0193]
In the above case, the diffraction spots located in the film thickness direction are preferably equivalent crystal planes typically represented as {111} planes.
[0194]
Alternatively, in the spin valve thin film element shown in FIG. 2, transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3 obtained by making an electron beam (beam) incident from a direction perpendicular to the interface are respectively Diffraction spots corresponding to the reciprocal lattice points representing the crystal planes of the layers of the above-mentioned layer appeared, and the same indexing was made in the diffraction image of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3 among the diffraction spots. An imaginary line connecting a certain diffraction spot to the beam origin is shifted from the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Alternatively, of the diffraction spots, a certain diffraction index spot appears only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0195]
  In the above case, the direction perpendicular to the interface is typically the direction of the equivalent crystal axis represented as the <111> direction, or the crystal plane parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer is Typically{111}It is preferably an equivalent crystal plane expressed as a plane.
[0196]
When the transmission electron beam diffraction image as described above is obtained, the anti-ferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film surface, and exist in the crystal plane. It can be assumed that at least some of the same equivalent crystal axes are directed in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0197]
In the spin valve thin film element having the above transmission electron beam diffraction image, the antiferromagnetic layer 4 has undergone appropriate regular transformation by heat treatment, and a larger exchange coupling magnetic field can be obtained than in the prior art.
[0198]
In the spin valve thin film element shown in FIG. 2, the composition ratio of the element X or the element X + X ′ constituting the antiferromagnetic layer 4 is preferably 45 (at%) or more and 60 (at%) or less. This gives 1.58 × 10^FourAn exchange coupling magnetic field of (A / m) or more can be obtained.
[0199]
In the present invention, the composition ratio of the element X or the element X + X ′ is preferably 49 (at%) or more and 57 (at%) or less. As a result, 7.9 × 10^FourAn exchange coupling magnetic field of (A / m) or more can be obtained.
[0200]
Next, FIG. 3 is a partial sectional view showing the structure of another spin-valve type thin film element in the present invention.
[0201]
In FIG. 3, the underlayer 6, the seed layer 22, the antiferromagnetic layer 4, the pinned magnetic layer 3, the nonmagnetic intermediate layer 2, and the free magnetic layer 1 are laminated from the bottom.
[0202]
The underlayer 6 is preferably formed of at least one element selected from Ta, Hf, Nb, Zr, Ti, Mo, and W.
[0203]
  The seed layer 22 is typically composed of a face-centered cubic crystal and is typically in a direction parallel to the interface with the antiferromagnetic layer 4.{111}It is preferable that an equivalent crystal plane represented as a plane is preferentially oriented. The material of the seed layer 22 is the same as that described with reference to FIG.
[0204]
By forming the seed layer 22 under the antiferromagnetic layer 4, the antiferromagnetic layer 4, the pinned magnetic layer 3, the nonmagnetic intermediate layer 2, and the free magnetic layer 1 formed on the seed layer 22 are also described above. The same crystal plane as the seed layer 22 is preferentially oriented in a direction parallel to the film surface.
[0205]
In FIG. 3, the pinned magnetic layer 3 is formed of a three-layer film of Co films 11 and 13 and a Ru film 12. However, other materials may be used. May be formed.
[0206]
The free magnetic layer 1 is formed of a two-layer film of a NiFe alloy film 9 and a Co film 10, but other materials may be used. For example, the free magnetic layer 1 is formed of a single-layer film instead of the two-layer film. It doesn't matter.
[0207]
In the spin-valve type thin film element shown in FIG. 3, the antiferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film plane, and exist in the crystal plane. At least some of the equivalent crystal axes are oriented in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0208]
Further, when the antiferromagnetic layer 4 and the pinned magnetic layer 3 are viewed in a cross section from a direction parallel to the film thickness (Z direction in the drawing), the crystal grain boundaries of the antiferromagnetic layer 4 and the crystals of the pinned magnetic layer 3 are observed. The grain boundary is in a discontinuous state at least at a part of the interface.
[0209]
For this reason, at least a part of the interface is kept in an inconsistent state, and the antiferromagnetic layer 4 has been subjected to appropriate regular transformation by heat treatment, so that a large exchange coupling magnetic field can be obtained.
[0210]
  The antiferromagnetic layer 4 and the pinned magnetic layer 3 are typically in a direction parallel to the film surface.{111}It is preferable that an equivalent crystal plane represented as a plane is preferentially oriented. In the crystal plane, it is preferable that the directions of equivalent crystal axes, which are typically expressed as <110> directions, are different from each other in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0211]
In the spin-valve type thin film element shown in FIG. 3, the transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3 obtained by making an electron beam (beam) incident from a direction parallel to the interface are respectively A diffraction spot corresponding to a reciprocal lattice point representing each crystal plane of the layer of the magnetic layer appears, and the diffraction index of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3 are indexed in the same manner and the beam out of the diffraction spots. A first imaginary line connecting a diffraction spot showing a certain crystal plane located in the film thickness direction when viewed from the origin and the beam origin is a diffraction image of the antiferromagnetic layer and a diffraction image of the ferromagnetic layer. Are consistent with each other.
[0212]
Moreover, in the present invention, the second imaginary line connecting the beam origin and the diffraction spot indicating a certain crystal plane, which is indexed and located in a direction other than the film thickness direction when viewed from the beam origin. Are shifted from each other in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Further, when viewed from the beam origin, diffraction spots indicating a crystal plane located in directions other than the film thickness direction appear only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0213]
In the above case, the diffraction spots located in the film thickness direction are preferably equivalent crystal planes typically represented as {111} planes.
[0214]
Alternatively, in the spin valve thin film element shown in FIG. 3, the transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3 obtained by making an electron beam (beam) incident from the direction perpendicular to the interface are respectively Diffraction spots corresponding to the reciprocal lattice points representing the crystal planes of the layers of the above-mentioned layer appeared, and the same indexing was made in the diffraction image of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3 among the diffraction spots. An imaginary line connecting a certain diffraction spot to the beam origin is shifted from the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Alternatively, of the diffraction spots, a certain diffraction index spot appears only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0215]
  In the above case, the direction perpendicular to the interface is the direction of the equivalent crystal axis typically represented as the <111> direction, or the crystal plane parallel to the interface of the antiferromagnetic layer and the ferromagnetic layer Is typically{111}It is preferably an equivalent crystal plane expressed as a plane.
[0216]
When the transmission electron beam diffraction image as described above is obtained, the anti-ferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film surface, and exist in the crystal plane. It can be assumed that at least some of the same equivalent crystal axes are directed in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3. In the spin-valve type thin film element having the transmission electron beam diffraction image described above, the antiferromagnetic layer 4 has undergone appropriate regular transformation by heat treatment, and a larger exchange coupling magnetic field can be obtained than in the prior art.
[0217]
In the spin valve thin film element shown in FIG. 3, the composition ratio of the element X or the element X + X ′ constituting the antiferromagnetic layer 4 is preferably 45 (at%) or more and 60 (at%) or less. This gives 1.58 × 10^FourAn exchange coupling magnetic field of (A / m) or more can be obtained.
[0218]
In the present invention, the composition ratio of the element X or the element X + X ′ is preferably 49 (at%) or more and 56.5 (at%) or less. As a result, 7.9 × 10^FourAn exchange coupling magnetic field of (A / m) or more can be obtained.
[0219]
As shown in FIG. 3, exchange bias layers (antiferromagnetic layers) 16 and 16 are formed on the free magnetic layer 1 with an interval of the track width Tw in the track width direction (X direction in the drawing). .
[0220]
The exchange bias layer 16 is made of an X—Mn alloy (where X is one or more elements selected from Pt, Pd, Ir, Rh, Ru, and Os), preferably a PtMn alloy, or X-Mn-X 'alloy (where X' is Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti, V, Cr, Fe, Co, Ni, Cu , Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, and rare earth elements are one or more elements. ing.
[0221]
In the present invention, the exchange bias layer 16 and the free magnetic layer 1 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film plane, and at least one of the same equivalent crystal axes existing in the crystal plane. The directions of the portions of the exchange bias layer 16 and the free magnetic layer 1 are different from each other.
[0222]
Further, when the exchange bias layer 16 and the free magnetic layer 1 are viewed in a cross section from a direction parallel to the film thickness (Z direction in the drawing), the crystal grain boundary of the exchange bias layer 16 and the crystal grain boundary of the free magnetic layer 1 Is discontinuous in at least part of the interface.
[0223]
For this reason, at least a part of the interface is kept in an inconsistent state, and the exchange bias layer 16 has been subjected to appropriate regular transformation by heat treatment, so that a large exchange coupling magnetic field can be obtained.
[0224]
  The exchange bias layer 16 and the free magnetic layer 1 are typically in a direction parallel to the film surface.{111}It is preferable that an equivalent crystal plane represented as a plane is preferentially oriented. In the crystal plane, it is preferable that the directions of equivalent crystal axes, which are typically expressed as <110> directions, are different from each other in the exchange bias layer 16 and the free magnetic layer 1.
[0225]
Further, in the spin-valve type thin film element shown in FIG. 3, transmission electron beam diffraction images of the exchange bias layer 16 and the free magnetic layer 1 obtained by making an electron beam (beam) incident in a direction parallel to the interface include A diffraction spot corresponding to a reciprocal lattice point representing each crystal plane of the layer appears, and among the diffraction spots, the diffraction index of the exchange bias layer 16 and the diffraction pattern of the free magnetic layer 1 are indexed in the same way and from the beam origin. A first imaginary line connecting a diffraction spot showing a certain crystal plane and located at the beam origin when viewed in the film thickness direction is mutually in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Match.
[0226]
Moreover, in the present invention, the second imaginary line connecting the beam origin and the diffraction spot indicating a certain crystal plane, which is indexed and located in a direction other than the film thickness direction when viewed from the beam origin. Are shifted from each other in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Or, when viewed from the beam origin, diffraction spots indicating a crystal plane located in directions other than the film thickness direction appear only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0227]
In the above case, the diffraction spots located in the film thickness direction are preferably equivalent crystal planes typically represented as {111} planes.
[0228]
Alternatively, in the spin valve thin film element shown in FIG. 3, transmission electron beam diffraction images of the exchange bias layer 16 and the free magnetic layer 1 obtained by making an electron beam (beam) incident from the direction perpendicular to the interface include A diffraction spot corresponding to a reciprocal lattice point representing each crystal plane of the layer appears. Among the diffraction spots, the diffraction index of the exchange bias layer 16 and the diffraction pattern of the free magnetic layer 1 are given the same index. An imaginary line connecting the spot to the beam origin is shifted from the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Alternatively, of the diffraction spots, a certain diffraction index spot appears only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0229]
  In the above case, the direction perpendicular to the interface is the direction of the equivalent crystal axis typically represented as the <111> direction, or the crystal plane parallel to the interface of the antiferromagnetic layer and the ferromagnetic layer Is typically{111}It is preferably an equivalent crystal plane expressed as a plane.
[0230]
In the spin valve thin film element having the transmission electron diffraction image as described above, the exchange bias layer 16 and the free magnetic layer 1 are preferentially oriented in the same equivalent crystal plane in the direction parallel to the film plane, and the crystal It is presumed that at least some of the same equivalent crystal axes existing in the plane face in different directions in the exchange bias layer 16 and the free magnetic layer 1. In the spin-valve type thin film element having the transmission electron beam diffraction image, the exchange bias layer 16 has undergone appropriate regular transformation by heat treatment, and a large exchange coupling magnetic field can be obtained compared to the conventional case.
[0231]
At both ends of the free magnetic layer 1, the free magnetic layer 1 is made into a single magnetic domain in the X direction in the figure by the exchange coupling magnetic field between the exchange bias layers 16, and the magnetization of the track width Tw region of the free magnetic layer 1 is external. Appropriately aligned in the X direction in the figure to the extent that it reacts to a magnetic field.
[0232]
In the single spin valve magnetoresistive element thus formed, the magnetization in the track width Tw region of the free magnetic layer 1 changes from the X direction to the Y direction in the drawing by an external magnetic field in the Y direction in the drawing. The electrical resistance changes depending on the relationship between the change in the magnetization direction in the free magnetic layer 1 and the fixed magnetization direction (Y direction in the figure) of the fixed magnetic layer 3, and the voltage change based on the change in the electrical resistance value A leakage magnetic field from the recording medium is detected.
[0233]
FIG. 4 is a partial sectional view showing the structure of another spin-valve type thin film element in the present invention.
[0234]
In the spin-valve type thin film element shown in FIG. 4, a pair of seed layers 22 spaced apart by a track width Tw is formed in the track width direction (X direction in the drawing), and exchange bias layers 16 and 16 are formed on the seed layer 22. Is formed.
[0235]
Between the pair of seed layers 22 and the exchange bias layer 16 is SiO.₂And Al₂O_ThreeThe insulating layer 17 is made of an insulating material such as.
[0236]
A free magnetic layer 1 is formed on the exchange bias layer 16 and the insulating layer 17.
[0237]
The exchange bias layer 16 is formed of an X—Mn alloy or an X—Mn—X ′ alloy, and the composition ratio of the element X or the element X + X ′ is 45 (at%) or more and 60 (at%) or less. Preferably, it is 49 (at%) or more and 56.5 (at%) or less.
[0238]
By performing the heat treatment, the exchange bias layer 16 is not restricted by the crystal structure of the free magnetic layer 1 and undergoes an appropriate regular transformation, so that a larger exchange coupling magnetic field can be obtained compared to the conventional case.
[0239]
In the present invention, after the heat treatment, the exchange bias layer 16 and the free magnetic layer 1 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film surface, and exist in the crystal plane. Of the exchange bias layer 16 and the free magnetic layer 1 are directed in different directions.
[0240]
Further, when the exchange bias layer 16 and the free magnetic layer 1 are viewed in a cross section from a direction parallel to the film thickness (Z direction in the drawing), the crystal grain boundary of the exchange bias layer 16 and the crystal grain boundary of the free magnetic layer 1 Is discontinuous in at least part of the interface.
[0241]
For this reason, at least a part of the interface is kept in an inconsistent state, and the exchange bias layer 16 has been subjected to appropriate regular transformation by heat treatment, so that a large exchange coupling magnetic field can be obtained.
[0242]
The exchange bias layer 16 and the free magnetic layer 1 are preferably preferentially oriented in equivalent crystal planes typically represented as [111] planes in a direction parallel to the film plane. In the crystal plane, it is preferable that the directions of equivalent crystal axes, which are typically expressed as <110> directions, are different from each other in the exchange bias layer 16 and the free magnetic layer 1.
[0243]
Further, in the spin-valve type thin film element shown in FIG. 4, transmission electron beam diffraction images of the exchange bias layer 16 and the free magnetic layer 1 obtained by making an electron beam (beam) incident from a direction parallel to the interface include A diffraction spot corresponding to a reciprocal lattice point representing each crystal plane of the layer appears, and among the diffraction spots, the diffraction index of the exchange bias layer 16 and the diffraction pattern of the free magnetic layer 1 are indexed in the same way and from the beam origin. A first imaginary line connecting a diffraction spot showing a certain crystal plane and located at the beam origin when viewed in the film thickness direction is mutually in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Match.
[0244]
Moreover, in the present invention, the second imaginary line connecting the diffraction origin showing a certain crystal plane and the beam origin, which is the same indexing and is located in a direction other than the film thickness direction when viewed from the origin, The diffraction pattern of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer are shifted from each other. Alternatively, when viewed from the beam origin, diffraction spots indicating a crystal plane located in a direction other than the film thickness direction appear only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0245]
In the above case, it is preferable that the diffraction spots located in the film thickness direction show an equivalent crystal plane typically represented as a {111} plane.
[0246]
Alternatively, in the spin valve thin film element shown in FIG. 4, transmission electron beam diffraction images of the exchange bias layer 16 and the free magnetic layer 1 obtained by making an electron beam (beam) incident from a direction perpendicular to the interface include A diffraction spot corresponding to a reciprocal lattice point representing each crystal plane of the layer appears. Among the diffraction spots, the diffraction index of the exchange bias layer 16 and the diffraction pattern of the free magnetic layer 1 are given the same index. An imaginary line connecting the spot to the beam origin is shifted from the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Alternatively, of the diffraction spots, a certain diffraction index spot appears only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0247]
  In the above case, the direction perpendicular to the interface is the direction of the equivalent crystal axis typically represented as the <111> direction, or the crystal plane parallel to the interface of the antiferromagnetic layer and the ferromagnetic layer Is typically{111}It is preferably an equivalent crystal plane expressed as a plane.
[0248]
When the transmission electron beam diffraction image as described above is obtained, the exchange bias layer 16 and the free magnetic layer 1 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film surface, and exist in the crystal plane. It can be presumed that at least a part of the same equivalent crystal axes are directed in different directions in the exchange bias layer 16 and the free magnetic layer 1. In the above-described spin-valve type thin film element, the exchange bias layer 16 has undergone appropriate regular transformation by heat treatment, and a larger exchange coupling magnetic field can be obtained than in the conventional case.
[0249]
At both ends of the free magnetic layer 1, a single magnetic domain is formed in the X direction in the figure by an exchange coupling magnetic field between the exchange bias layers 16, and the magnetization in the track width Tw region of the free magnetic layer 1 reacts to an external magnetic field. To the extent that is appropriate, it is aligned in the X direction in the figure.
[0250]
As shown in FIG. 4, a nonmagnetic intermediate layer 2 is formed on the free magnetic layer 1, and a pinned magnetic layer 3 is formed on the nonmagnetic intermediate layer 2. Further, an antiferromagnetic layer 4 is formed on the pinned magnetic layer 3.
[0251]
In the present invention, after the heat treatment, the antiferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film surface, and exist in the crystal plane. At least a part of the axis faces different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0252]
Further, when the antiferromagnetic layer 4 and the pinned magnetic layer 3 are viewed in a cross section from a direction parallel to the film thickness (Z direction in the drawing), the crystal grain boundaries of the antiferromagnetic layer 4 and the crystals of the pinned magnetic layer 3 are observed. The grain boundary is in a discontinuous state at least at a part of the interface.
[0253]
For this reason, at least a part of the interface is kept in an inconsistent state, and the antiferromagnetic layer 4 has been subjected to appropriate regular transformation by heat treatment, so that a large exchange coupling magnetic field can be obtained.
[0254]
  The antiferromagnetic layer 4 and the pinned magnetic layer 3 are typically in a direction parallel to the film surface.{111}It is preferable that an equivalent crystal plane represented as a plane is preferentially oriented. In the crystal plane, it is preferable that the directions of equivalent crystal axes, which are typically expressed as <110> directions, are different from each other in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0255]
In the spin-valve type thin film element shown in FIG. 4, the transmission electron beam diffraction images of the antiferromagnetic layer layer 4 and the pinned magnetic layer 3 obtained by making an electron beam (beam) incident from a direction parallel to the interface include: Diffraction spots corresponding to reciprocal lattice points representing each crystal plane of each layer appear, and the same indexing is made between the diffraction image of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3 among the diffraction spots. A first phantom line connecting a diffraction spot indicating a crystal plane located in the film thickness direction when viewed from the beam origin and the beam origin is a diffraction image of the antiferromagnetic layer and a diffraction image of the ferromagnetic layer. And are consistent with each other.
[0256]
Moreover, in the present invention, the second imaginary line connecting the beam origin and the diffraction spot indicating a certain crystal plane, which is indexed and located in a direction other than the film thickness direction when viewed from the beam origin. Are shifted from each other in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Alternatively, when viewed from the beam origin, diffraction spots indicating a crystal plane located in a direction other than the film thickness direction appear only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0257]
In the above case, it is preferable that the diffraction spots located in the film thickness direction show an equivalent crystal plane typically represented as a {111} plane.
[0258]
Alternatively, in the spin valve thin film element shown in FIG. 4, the transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3 obtained by making an electron beam (beam) incident from the direction perpendicular to the interface are respectively Diffraction spots corresponding to the reciprocal lattice points representing the crystal planes of the layers of the above-mentioned layer appeared, and the same indexing was made in the diffraction image of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3 among the diffraction spots. An imaginary line connecting a certain diffraction spot to the beam origin is shifted from the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Alternatively, of the diffraction spots, a certain diffraction index spot appears only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0259]
  In the above case, the direction perpendicular to the interface is typically the direction of the equivalent crystal axis represented as the <111> direction, or the crystal plane parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer is Typically{111}It is preferably an equivalent crystal plane expressed as a plane.
[0260]
When the transmission electron beam diffraction image as described above is obtained, the anti-ferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film surface, and exist in the crystal plane. It can be inferred that at least some of the same equivalent crystal axes are oriented in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3. In the spin valve thin film element having the above transmission electron beam diffraction image, the antiferromagnetic layer 4 has undergone appropriate regular transformation by heat treatment, and a larger exchange coupling magnetic field can be obtained than in the prior art.
[0261]
FIG. 5 is a partial sectional view showing the structure of a dual spin-valve type thin film element in the present invention.
[0262]
As shown in FIG. 5, the underlayer 6, the seed layer 22, the antiferromagnetic layer 4, the pinned magnetic layer 3, the nonmagnetic intermediate layer 2, and the free magnetic layer 1 are sequentially stacked from below. The free magnetic layer 1 is formed of a three-layer film, and is composed of, for example, Co films 10 and 10 and a NiFe alloy film 9. Further, a nonmagnetic intermediate layer 2, a pinned magnetic layer 3, an antiferromagnetic layer 4, and a protective layer 7 are successively stacked on the free magnetic layer 1.
[0263]
Hard bias layers 5 and 5 and conductive layers 8 and 8 are laminated on both sides of the multilayer film from the base layer 6 to the protective layer 7. Each layer is formed of the same material as described in FIG.
[0264]
In this embodiment, a seed layer 22 is formed under the antiferromagnetic layer 4 located below the free magnetic layer 1 in the drawing. Further, the composition ratio of the element X or the element X + X ′ constituting the antiferromagnetic layer 4 is preferably 45 (at%) or more and 60 (at%) or more, more preferably 49 (at%) or more. It is 56.5 (at%) or less.
[0265]
In the present invention, after the heat treatment, the crystal orientation of the antiferromagnetic layer 4 and the pinned magnetic layer 3 is preferentially the same equivalent crystal plane in the direction parallel to the interface between the antiferromagnetic layer 4 and the pinned magnetic layer 3. At least some of the same equivalent crystal axes that are oriented and exist within the crystal planes of the antiferromagnetic layer 4 and the pinned magnetic layer 3 are oriented in different directions.
[0266]
Further, when the antiferromagnetic layer 4 and the pinned magnetic layer 3 are viewed in a cross section from a direction parallel to the film thickness (Z direction in the drawing), the crystal grain boundaries of the antiferromagnetic layer 4 and the crystals of the pinned magnetic layer 3 are observed. The grain boundary is in a discontinuous state at least at a part of the interface.
[0267]
For this reason, at least a part of the interface is kept in an inconsistent state, and the antiferromagnetic layer 4 has been subjected to appropriate regular transformation by heat treatment, so that a large exchange coupling magnetic field can be obtained.
[0268]
  The antiferromagnetic layer 4 and the pinned magnetic layer 3 are typically in a direction parallel to the film surface.{111}It is preferable that an equivalent crystal plane represented as a plane is preferentially oriented. In the crystal plane, it is preferable that the directions of equivalent crystal axes, which are typically expressed as <110> directions, are different from each other in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0269]
In the dual spin-valve type thin film element shown in FIG. 5, not only the fixed magnetic layer 3 and the antiferromagnetic layer 4 formed below the free magnetic layer 1, but also the crystal orientation of the entire laminated film is the same as described above. The crystal orientation is as follows.
[0270]
In other words, in the present invention, the antiferromagnetic layer 4 and the pinned magnetic layer 3 formed above the free magnetic layer 1 are also preferentially oriented in the same equivalent crystal plane in the direction parallel to the film plane, and in the crystal plane. In other words, at least a part of the same equivalent crystal axis exists in the antiferromagnetic layer 4 and the pinned magnetic layer 3 in different directions.
[0271]
Further, when the antiferromagnetic layer 4 and the pinned magnetic layer 3 are viewed in a cross section from a direction parallel to the film thickness (Z direction in the drawing), the crystal grain boundaries of the antiferromagnetic layer 4 and the crystals of the pinned magnetic layer 3 are observed. The grain boundary is in a discontinuous state at least at a part of the interface.
[0272]
For this reason, at least a part of the interface is kept in an inconsistent state, and the antiferromagnetic layer 4 has been subjected to appropriate regular transformation by heat treatment, so that a large exchange coupling magnetic field can be obtained.
[0273]
  The antiferromagnetic layer 4 and the pinned magnetic layer 3 are typically in a direction parallel to the film surface.{111}It is preferable that an equivalent crystal plane represented as a plane is preferentially oriented. In the crystal plane, it is preferable that the directions of equivalent crystal axes, which are typically expressed as <110> directions, are different from each other in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0274]
In the spin valve thin film element shown in FIG. 5, the transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3 obtained by making an electron beam (beam) incident from a direction parallel to the interface are Diffraction spots corresponding to reciprocal lattice points representing each crystal plane of each layer appear, and the same indexing is made between the diffraction image of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3 among the diffraction spots. A first phantom line connecting a diffraction spot indicating a crystal plane located in the film thickness direction when viewed from the beam origin and the beam origin is a diffraction image of the antiferromagnetic layer and a diffraction image of the ferromagnetic layer. And match each other.
[0275]
Moreover, in the present invention, the second imaginary line connecting the beam origin and the diffraction spot indicating a certain crystal plane, which is indexed and located in a direction other than the film thickness direction when viewed from the beam origin. Are shifted from each other in the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Alternatively, when viewed from the beam origin, diffraction spots indicating a crystal plane located in a direction other than the film thickness direction appear only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0276]
In the above case, it is preferable that the diffraction spots located in the film thickness direction show an equivalent crystal plane typically represented as a {111} plane.
[0277]
Alternatively, in the spin valve thin film element shown in FIG. 5, the transmission electron beam diffraction images of the antiferromagnetic layer 4 and the pinned magnetic layer 3 obtained by making an electron beam (beam) incident from the direction perpendicular to the interface are as follows: Diffraction spots corresponding to reciprocal lattice points representing the crystal planes of the respective layers appear, and the same indexing is made between the diffraction image of the antiferromagnetic layer 4 and the diffraction image of the pinned magnetic layer 3 among the diffraction spots. An imaginary line connecting a certain diffraction spot to the beam origin is shifted from the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Alternatively, of the diffraction spots, a certain diffraction index spot appears only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0278]
  In the above case, the direction perpendicular to the interface is the direction of the equivalent crystal axis typically represented as the <111> direction, or the crystal plane parallel to the interface of the antiferromagnetic layer and the ferromagnetic layer Is typically{111}It is preferably an equivalent crystal plane expressed as a plane.
[0279]
When the transmission electron beam diffraction image as described above is obtained, the anti-ferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film surface, and exist in the crystal plane. It is presumed that at least some of the same equivalent crystal axes are oriented in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3. Therefore, in the spin-valve type thin film element having the transmission electron beam diffraction image described above, the antiferromagnetic layer 4 has undergone appropriate regular transformation by heat treatment, and a larger exchange coupling magnetic field can be obtained than in the conventional case.
[0280]
6 and 7 are cross-sectional views showing the structure of the AMR magnetoresistive element of the present invention. As shown in FIG. 6, a soft magnetic layer (SAL layer) 18, a nonmagnetic layer (SHUNT layer) 19, and a magnetoresistive layer (MR layer) 20 are successively stacked from the bottom.
[0281]
For example, the soft magnetic layer 18 is made of an Fe—Ni—Nb alloy, the nonmagnetic layer 19 is made of a Ta film, and the magnetoresistive layer 20 is made of a NiFe alloy.
[0282]
On the magnetoresistive layer 20, exchange bias layers (antiferromagnetic layers) 21 and 21 are formed on both sides in the track width direction (X direction) with the track width Tw opened. Although not shown, the conductive layer is formed on the exchange bias layers 21 and 21, for example.
[0283]
In FIG. 7, a pair of seed layers 22 is formed with an interval of the track width Tw in the track width direction (X direction in the drawing). Exchange bias layers 21 and 21 are formed on the seed layer 22, and the gap between the pair of seed layers 22 and the exchange bias layers 21 and 21 is SiO.₂And Al₂O_ThreeThe insulating layer 26 is made of an insulating material such as.
[0284]
A magnetoresistive layer (MR layer) 20, a nonmagnetic layer (SHUNT layer) 19, and a soft magnetic layer (SAL layer) 18 are stacked on the exchange bias layers 21, 21 and the insulating layer 26.
[0285]
In the present invention, the exchange bias layer 21 and the magnetoresistive layer 20 shown in FIGS. 6 and 7 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film plane, and are present in the crystal plane. At least a part of the crystal axis is directed in different directions between the exchange bias layer 21 and the magnetoresistive layer 20.
[0286]
Further, when the exchange bias layer 21 and the magnetoresistive layer 20 are viewed in a cross section from a direction parallel to the film thickness (Z direction in the drawing), the crystal grain boundary of the exchange bias layer 21 and the crystal grain boundary of the magnetoresistive layer 20 are shown. Is discontinuous in at least part of the interface.
[0287]
For this reason, at least a part of the interface is kept in an inconsistent state, and the exchange bias layer 21 has been subjected to appropriate regular transformation by heat treatment, so that a large exchange coupling magnetic field can be obtained.
[0288]
  The exchange bias layer 21 and the magnetoresistive layer 20 are typically in a direction parallel to the film surface.{111}It is preferable that an equivalent crystal plane represented as a plane is preferentially oriented. Also, in the crystal plane, it is preferable that the direction of the equivalent crystal axis, which is typically expressed as the <110> direction, is different in the exchange bias layer 21 and the magnetoresistive layer 20.
[0289]
6 and 7, the transmission electron beam diffraction images of the exchange bias layer 21 and the magnetoresistive layer 20 obtained by making an electron beam (beam) incident from the direction parallel to the interface are respectively A diffraction spot corresponding to a reciprocal lattice point representing each crystal plane of the layer of the magnetic layer appears, and the diffraction index of the exchange bias layer 21 and the diffraction image of the magnetoresistive layer 20 among the diffraction spots are indexed and the beam origin. A first imaginary line connecting a diffraction spot showing a certain crystal plane, which is located in the film thickness direction when viewed from the viewpoint, and the beam origin is represented by a diffraction image of the antiferromagnetic layer and a diffraction image of the ferromagnetic layer. Are consistent with each other.
[0290]
In addition, in the present invention, the second imaginary line connecting the origin and the diffraction spot indicating a certain crystal plane, which is indexed and located in a direction other than the film thickness direction when viewed from the origin, The diffraction pattern of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer are shifted from each other. Alternatively, when viewed from the beam origin, diffraction spots indicating a crystal plane located in a direction other than the film thickness direction appear only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0291]
In the above case, it is preferable that the diffraction spots located in the film thickness direction show an equivalent crystal plane typically represented as a {111} plane.
[0292]
Alternatively, in the AMR thin film element shown in FIGS. 6 and 7, transmission electron beam diffraction images of the exchange bias layer 21 and the magnetoresistive layer 20 obtained by making an electron beam (beam) incident from a direction perpendicular to the interface are respectively The diffraction spots corresponding to the reciprocal lattice points representing the crystal planes of the layer of the magnetic layer appear, and among the diffraction spots, the diffraction index image of the exchange bias layer 21 and the diffraction image of the magnetoresistive layer 20 are indexed the same. The imaginary line connecting the diffraction spot to the beam origin is shifted from the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer. Alternatively, of the diffraction spots, a certain diffraction index spot appears only in one diffraction image of the antiferromagnetic layer or the ferromagnetic layer.
[0293]
  In the above case, the direction perpendicular to the interface is the direction of the equivalent crystal axis typically represented as the <111> direction, or the crystal plane parallel to the interface of the antiferromagnetic layer and the ferromagnetic layer Is typically{111}It is preferably an equivalent crystal plane expressed as a plane.
[0294]
When the transmission electron beam diffraction image as described above is obtained, the exchange bias layer 21 and the magnetoresistive layer 20 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film surface, and exist in the crystal plane. It is considered that at least some of the same equivalent crystal axes are oriented in different directions in the exchange bias layer 21 and the magnetoresistive layer 20. In the spin-valve type thin film element having the above-mentioned transmission electron beam diffraction image, the exchange bias layer 21 has undergone appropriate regular transformation by heat treatment, and a large exchange coupling magnetic field can be obtained as compared with the conventional case.
[0295]
In the AMR type thin film element shown in FIGS. 6 and 7, the E of the magnetoresistive layer 20 shown in FIGS. 6 and 7 is generated by the exchange coupling magnetic field generated at the interface between the exchange bias layers 21 and 21 and the magnetoresistive layer 20. The region is made into a single magnetic domain in the X direction shown in the figure. Induced by this, the magnetization of the D region of the magnetoresistive layer 20 is aligned in the X direction in the figure. Further, a current magnetic field generated when the detection current flows through the magnetoresistive layer 20 is applied to the soft magnetic layer 18 in the Y direction, and the magnetostatic coupling energy provided by the soft magnetic layer 18 causes the D region of the magnetoresistive layer 20 to enter the D region. A lateral bias magnetic field is applied in the Y direction. When this lateral bias layer is applied to the D region of the magnetoresistive layer 20 that is single-domained in the X direction, the resistance change with respect to the magnetic field change in the D region of the magnetoresistive layer 20 (magnetoresistance effect characteristics: HR effect characteristics) ) Is set to have a linearity.
[0296]
The moving direction of the recording medium is the Z direction. When a leakage magnetic field is applied in the Y direction in the figure, the resistance value of the D region of the magnetoresistive layer 20 changes, and this is detected as a voltage change.
[0297]
In addition, although it is about the manufacturing method of the magnetoresistive effect element shown in above-mentioned FIG. 1 thru | or 7, in this invention, it is preferable to form the antiferromagnetic layer 4 as follows especially.
[0298]
As described above, the composition ratio of the element X or the element X + X ′ of the antiferromagnetic layer 4 is preferably 45 (at%) or more and 60 (at%) or less, more preferably 49 (at%) or more. If it is 56.5 (at%) or less, and it is within this range, it is possible to obtain a large exchange coupling magnetic field as shown in the experimental results described later.
[0299]
Therefore, as one manufacturing method, the antiferromagnetic layer 4 may be formed within the above composition range in the film forming stage, and further each other layer may be formed, and then heat treatment may be performed.
[0300]
In the present invention, after the heat treatment, the interface between the antiferromagnetic layer 4 and the pinned magnetic layer 3, the interface between the exchange bias layer 16 and the free magnetic layer 1, the interface between the exchange bias layer 21 and the magnetoresistive layer 20, and When the seed layer 22 is formed, at least a part of the interface between the seed layer 22 and the antiferromagnetic layer 4 and the interface between the seed layer 22 and the exchange bias layers 16 and 21 are in an inconsistent state. However, the non-alignment state is preferably maintained from the film formation stage. This is because, when the interface is in an aligned state in the film formation stage, it is considered that the antiferromagnetic layer 4 and the like are unlikely to cause appropriate regular transformation even if heat treatment is performed.
[0301]
In order to keep the interface in an inconsistent state in the film formation stage, it is preferable to form the antiferromagnetic layer 4 and the like by the following method, for example.
[0302]
FIG. 8 is a schematic diagram showing a state in which each layer of the laminated film shown in FIG. 1 is formed. As shown in FIG. 8, after forming the seed layer 22 on the underlayer 6, the antiferromagnetic layer 4 is formed of a three-layer film. The first antiferromagnetic layer 23, the second antiferromagnetic layer 24, and the third antiferromagnetic layer 25 constituting the antiferromagnetic layer 4 are the X-Mn alloy, X-Mn-X 'described above. Made of alloy.
[0303]
However, in the film forming stage, the composition ratio of the element X or the element X + X ′ constituting the first and third antiferromagnetic layers 23 and 25 is set to the composition of the element X or the element X + X ′ of the second antiferromagnetic layer 24. More than the ratio.
[0304]
Further, the second antiferromagnetic layer 24 formed between the first antiferromagnetic layer 23 and the third antiferromagnetic layer 25 is ideally easy to transform from an irregular lattice to a regular lattice by heat treatment. It is made of an antiferromagnetic material having a close composition.
[0305]
Thus, the composition ratio of the element X or the element X + X ′ of the first antiferromagnetic layer 23 and the third antiferromagnetic layer 25 is set to the composition ratio of the element X or the element X + X ′ of the second antiferromagnetic layer 24. In order to make the antiferromagnetic layer 4 easily transform from an irregular lattice to a regular lattice when heat treatment is performed, the crystal of the fixed magnetic layer 3 and the seed layer 22 is formed at each interface. This is because it is necessary not to be restrained by the structure or the like.
[0306]
The composition ratio of the element X or the element X + X ′ in the first antiferromagnetic layer 23 and the third antiferromagnetic layer 25 is preferably 53 (at%) or more and 65 (at%) or less, more preferably. 55 (at%) or more and 60 (at%) or less. The film thicknesses of the first antiferromagnetic layer 23 and the third antiferromagnetic layer 25 are preferably 3 to 30 mm. For example, in the case of FIG. 8, the first and third antiferromagnetic layers 23 and 25 are each formed with a thickness of about 10 mm.
[0307]
The composition ratio of the element X or the element X + X ′ of the second antiferromagnetic layer 24 is 44 (at%) or more and 57 (at%) or less. Preferably, it is 46 (at%) or more and 55 (at%) or less. When the composition ratio of the element X or the element X + X ′ is within this range, the second antiferromagnetic layer 24 is easily transformed from an irregular lattice to a regular lattice by heat treatment. The film thickness of the second antiferromagnetic layer 24 is preferably 70 mm or more. In the case of the embodiment shown in FIG. 8, the thickness of the second antiferromagnetic layer 24 is about 100 mm.
[0308]
The antiferromagnetic layers 23, 24 and 25 are preferably formed by sputtering. At this time, it is preferable to form the first and third antiferromagnetic layers 23 and 25 at a lower sputtering gas pressure than the second antiferromagnetic layer 24. Thereby, the composition ratio of the element X or the element X + X ′ of the first and third antiferromagnetic layers 23 and 25 is larger than the composition ratio of the element X or the element X + X ′ of the second antiferromagnetic layer 24. Is possible.
[0309]
Alternatively, in the present invention, even when the antiferromagnetic layer 4 is not formed with the above-described three-layer film in the film formation stage (before heat treatment), the antiferromagnetic layer 4 is formed with a single layer by the following method. It can be formed by appropriately changing the composition ratio (atomic%) of element X or element X + X ′ in the thickness direction.
[0310]
First, when the antiferromagnetic layer 4 is formed by sputtering using an antiferromagnetic material containing the elements X and Mn or a target formed of the elements X, X ′ and Mn, the seed layer 22 is separated from the seed layer 22. Accordingly, the antiferromagnetic layer 4 is formed by gradually increasing the sputtering gas pressure, and at the stage where the antiferromagnetic layer 4 is formed by about half, this time, the sputtering gas pressure is gradually lowered and the remaining is left. The antiferromagnetic layer 4 is formed.
[0311]
According to this method, the composition ratio (atomic%) of the element X or the element X + X ′ gradually decreases from the interface with the seed layer 22 to the vicinity of the center of the film thickness of the antiferromagnetic layer 4. The ratio (atomic%) gradually increases from the vicinity of the center to the interface with the pinned magnetic layer 3.
[0312]
For this reason, the composition ratio (atomic%) of the element X or the element X + X ′ is the largest near the interface between the seed layer 22 and the pinned magnetic layer 3, and the antiferromagnetic layer 4 is the smallest near the center of the film thickness. It becomes possible to do.
[0313]
The composition of the element X or the element X + X ′ when the composition ratio of all elements constituting the antiferromagnetic layer 4 near the interface with the pinned magnetic layer 3 and the interface with the seed layer 22 is 100 at%. The ratio is preferably 53 at% or more and 65 at% or less, and more preferably 55 at% or more and 60 at% or less.
[0314]
In the vicinity of the center of the antiferromagnetic layer 4 in the film thickness direction, the composition ratio of the element X or the element X + X ′ is preferably 44 (at%) or more and 57 (at%) or less, more preferably 46 (at %) To 55 (at%). The antiferromagnetic layer 4 is preferably formed with a thickness of 76 mm or more.
[0315]
FIG. 9 is a schematic diagram of a spin valve thin film element showing a state after heat treatment is performed on the laminated film shown in FIG.
[0316]
In the present invention, the first and third antiferromagnetic layers 23 and 25 having a large composition ratio of the element X or the element X + X ′ are formed on the side in contact with the seed layer 22 and the pinned magnetic layer 3 as described above. In addition, since the second antiferromagnetic layer 24 is formed between the first and third antiferromagnetic layers 23 and 25, the second antiferromagnetic layer 24 is formed with a composition that easily transforms from an irregular lattice to a regular lattice by heat treatment. When the transformation proceeds in the portion of the second antiferromagnetic layer 24 by the heat treatment, composition diffusion occurs between the first and third antiferromagnetic layers 23 and 25 and the second antiferromagnetic layer 24. Therefore, even in the first and third antiferromagnetic layers 23 and 25, the disordered lattice to the regular lattice can be maintained while appropriately maintaining the mismatched state at the interface between the seed layer 22 and the pinned magnetic layer 3. To the antiferromagnetic layer 4 as a whole. It is possible to cause the Do transformation.
[0317]
In the spin-valve thin film element after the heat treatment, the antiferromagnetic layer 4 and the pinned magnetic layer 3 have the same equivalent crystal plane preferentially oriented in the direction parallel to the film plane, and exist in the crystal plane. At least some of the same equivalent crystal axes are oriented in different directions in the antiferromagnetic layer 4 and the pinned magnetic layer 3.
[0318]
Further, when the antiferromagnetic layer 4 and the pinned magnetic layer 3 are viewed in a cross section from a direction parallel to the film thickness (Z direction in the drawing), the crystal grain boundaries of the antiferromagnetic layer 4 and the crystals of the pinned magnetic layer 3 are observed. The grain boundary is in a discontinuous state at least at a part of the interface.
[0319]
The antiferromagnetic layer 4 after the heat treatment is considered to have a region where the ratio of atomic% of the element X or the element X + X ′ to Mn increases toward the seed layer 22 and the pinned magnetic layer 3.
[0320]
In the case of the spin-valve type thin film element shown in FIG. 2, the antiferromagnetic layer 4 may be formed of the above-described three-layer film. For example, the first antiferromagnetic layer 23 in contact with the fixed magnetic layer 3 side is protected. You may form with the 2 layer structure of the 2nd antiferromagnetic layer 24 which touches the layer 7 side. This is because in FIG. 2 there is no seed layer 22 as in FIG.
[0321]
When the antiferromagnetic layer 4 is formed as a two-layer film as described above, the antiferromagnetic layer 4 after the heat treatment has an element X or element X + X ′ with respect to Mn toward the pinned magnetic layer 3. It is considered that there is a region where the atomic percentage increases.
[0322]
In the case of the spin valve thin film element of FIG. 3, the exchange bias layer 16 is formed of a two-layer film as in the case of FIG. The first antiferromagnetic layer 23 is formed in contact with the free magnetic layer 1 side, and the second antiferromagnetic layer 24 is formed on the side away from the free magnetic layer 1.
[0323]
Further, the antiferromagnetic layer 4 shown in FIG. 3 is formed of a three-layer film as in the case of FIG. By performing the heat treatment, the exchange bias layer 16 and the antiferromagnetic layer 4 can undergo appropriate regular transformation, and a large exchange coupling magnetic field can be obtained.
[0324]
It is considered that the exchange bias layer 16 after the heat treatment has a region in which the ratio of atomic% of element X or element X + X ′ to Mn increases toward the free magnetic layer 1.
[0325]
Further, it is considered that the antiferromagnetic layer 4 after the heat treatment has a region in which the ratio of atomic% of element X or element X + X ′ to Mn increases toward the pinned magnetic layer 3 and the seed layer 22.
[0326]
Further, in the method of manufacturing the spin valve thin film element shown in FIG. 4, the antiferromagnetic layer 4 is formed of a two-layer film as in the case of FIG. The first antiferromagnetic layer 23 is formed in contact with the pinned magnetic layer 3 side, and the second antiferromagnetic layer 24 is formed on the side away from the pinned magnetic layer 3.
[0327]
The exchange bias layer 16 is formed of a three-layer film as in the case of the antiferromagnetic layer 4 in FIG. By performing the heat treatment, the exchange bias layer 16 and the antiferromagnetic layer 4 can undergo appropriate regular transformation, and a large exchange coupling magnetic field can be obtained.
[0328]
It is considered that the exchange bias layer 16 after the heat treatment has a region in which the ratio of atomic% of element X or element X + X ′ to Mn increases toward the free magnetic layer 1 and the seed layer 22.
[0329]
Further, it is considered that the antiferromagnetic layer 4 after the heat treatment has a region where the ratio of atomic% of element X or element X + X ′ to Mn increases toward the pinned magnetic layer 3.
[0330]
In the method of manufacturing the dual spin valve thin film element shown in FIG. 5, as shown in FIG. 10, the antiferromagnetic layer 4 positioned below the free magnetic layer 1 is replaced with the first antiferromagnetic layer 23, the second antiferromagnetic layer 23, and the second antiferromagnetic layer 23. Of the antiferromagnetic layer 24 and the third antiferromagnetic layer 25, and the antiferromagnetic layer 4 positioned above the free magnetic layer 1 is replaced with the first antiferromagnetic layer 14 and The second antiferromagnetic layer 15 is formed of a two-layer film.
[0331]
The thicknesses and compositions of the first antiferromagnetic layers 14, 23, the second antiferromagnetic layer 24, and the third antiferromagnetic layer 25 are the same as those described with reference to FIG.
[0332]
After film formation as shown in FIG. 10, heat treatment is performed. This state is shown in FIG. In FIG. 11, the three-layer film constituting the antiferromagnetic layer 4 formed below the free magnetic layer 1 causes compositional diffusion, and the antiferromagnetic layer 4 after the heat treatment includes a pinned magnetic layer. 3 and the seed layer 22, it is considered that there is a region where the ratio of atomic% of element X or element X + X ′ to Mn increases.
[0333]
The two-layer film constituting the antiferromagnetic layer 4 formed above the free magnetic layer 1 also causes compositional diffusion, and the antiferromagnetic layer 4 after the heat treatment is directed toward the pinned magnetic layer 3. Therefore, it is considered that there is a region where the ratio of atomic% of element X or element X + X ′ to Mn increases.
[0334]
Next, in the manufacturing method of the AMR type thin film element shown in FIG. 6, the exchange bias layer 21 is formed of a two-layer film in the same manner as the antiferromagnetic layer 4 formed on the upper side of the free magnetic layer 1 shown in FIG. . The exchange bias layer 21 is formed of a first antiferromagnetic layer 14 in contact with the magnetoresistive layer 20 and a second antiferromagnetic layer 15 formed on the side away from the magnetoresistive layer 20.
[0335]
When heat treatment is performed, the exchange bias layer 21 undergoes appropriate regular transformation, and a large exchange coupling magnetic field is generated between the exchange bias layer 21 and the magnetoresistive layer 20.
[0336]
In the exchange bias layer 21 after the heat treatment, it is considered that there is a region in which the ratio of atomic% of element X or element X + X ′ to Mn increases toward the magnetoresistive layer 20.
[0337]
Further, in the method of manufacturing the AMR type thin film element shown in FIG. 7, the exchange bias layer 21 is formed of a three-layer film similarly to the antiferromagnetic layer 4 shown in FIG. The exchange bias layer 21 includes a first antiferromagnetic layer 23 in contact with the magnetoresistive layer 20, a third antiferromagnetic layer 25 in contact with the seed layer 22, and the first and third antiferromagnetic layers 23. , 25, the second antiferromagnetic layer 24 is formed.
[0338]
When heat treatment is performed, the exchange bias layer 21 undergoes appropriate regular transformation, and a large exchange coupling magnetic field is generated between the exchange bias layer 21 and the magnetoresistive layer 20.
[0339]
In the exchange bias layer 21 after the heat treatment, it is considered that there is a region in which the ratio of atomic% of the element X or the element X + X ′ to Mn increases toward the magnetoresistive layer 20 and the seed layer 22.
[0340]
FIG. 12 is a cross-sectional view of the structure of the read head in which the magnetoresistive effect element shown in FIGS. 1 to 11 is formed, as viewed from the surface facing the recording medium.
[0341]
Reference numeral 40 denotes a lower shield layer formed of, for example, a NiFe alloy, and a lower gap layer 41 is formed on the lower shield layer 40. A magnetoresistive effect element 42 shown in FIGS. 1 to 7 is formed on the lower gap layer 41, and an upper gap layer 43 is formed on the magnetoresistive effect element 42. On the gap layer 43, an upper shield layer 44 made of a NiFe alloy or the like is formed.
[0342]
The lower gap layer 41 and the upper gap layer 43 are made of, for example, SiO.₂And Al₂O_ThreeIt is made of an insulating material such as (alumina). As shown in FIG. 12, the length from the lower gap layer 41 to the upper gap layer 43 is the gap length Gl. The smaller the gap length Gl, the higher the recording density can be accommodated.
[0343]
In the present invention, even if the thickness of the antiferromagnetic layer 4 is reduced, a large exchange coupling magnetic field can be generated. Therefore, the film thickness of the magnetoresistive effect element can be made smaller than before, and it is possible to manufacture a thin film magnetic head that can cope with high recording density by narrowing the gap.
[0344]
In the present invention, the embodiment in which the seed layer 22 is formed under the antiferromagnetic layer 4 (or the exchange bias layer 16 or the magnetoresistive layer 20) in FIGS. Although listed, it is not limited to this form.
[0345]
In the present invention, the crystal grain boundary of the antiferromagnetic layer 4 and the crystal grain boundary of the ferromagnetic layer are in a discontinuous state at least at a part of the interface on the cut surface cut in the direction parallel to the film thickness direction. However, in this case, the crystal orientations of the antiferromagnetic layer and the ferromagnetic layer may be differently preferentially oriented in a direction parallel to the film surface. Even in such a case, the antiferromagnetic layer can undergo appropriate regular transformation by heat treatment to obtain a large exchange coupling magnetic field.
[0346]
【Example】
In the present invention, the spin valve film having the film configuration described below is formed, and the relationship between the Pt amount and the exchange coupling magnetic field (Hex) is changed while changing the Pt amount of the PtMn alloy film constituting the antiferromagnetic layer. Examined.
[0347]
From the bottom, the membrane structure
Si substrate / alumina / underlayer: Ta (3 nm) / seed layer: NiFe (3 nm) / antiferromagnetic layer: Pt_xMn_100-x(15 nm) / pinned magnetic layer: [Co (1.5 nm) / Ru (0.8 nm) / Co (2.5 nm)] / nonmagnetic intermediate layer: Cu (2.3 nm) / free magnetic layer: [Co ( 1 nm) / NiFe (3 nm)] / backed layer: Cu (1.5 nm) / protective layer: Ta (3 nm)
The numerical values in parentheses written in each layer indicate the film thickness.
[0348]
After the spin valve film having the above film structure was formed, heat treatment was performed at 200 ° C. or more for 2 hours or more, and the exchange coupling magnetic field was measured. The experimental results are shown in FIG.
[0349]
As shown in FIG. 13, when the Pt amount X increases to about 50 (at%) to about 55 (at%), it can be seen that the exchange coupling magnetic field (Hex) also increases. It can also be seen that the exchange coupling magnetic field gradually decreases when the Pt amount X is about 55 (at%) or more.
[0350]
In the present invention, the exchange coupling magnetic field is 1.58 × 10 6. ^Four (A / m) or more was obtained as a preferable Pt amount, and the preferable Pt amount was set to 45 (at%) or more and 60 (at%) or less from the experimental results shown in FIG.
[0351]
In the present invention, the exchange coupling magnetic field is 7.9 × 10 6. ^Four A more preferable Pt amount was obtained when (A / m) or more was obtained, and a more preferable Pt amount was set to 49 (at%) or more and 56.5 (at%) or less from the experimental results shown in FIG.
[0352]
The change in the magnitude of the exchange coupling magnetic field depending on the amount of Pt as described above is because the state of the interface between the antiferromagnetic layer and the ferromagnetic layer (pinned magnetic layer) is changed by changing the amount of Pt. It is believed that there is.
[0353]
Here, it is known that the lattice constant of the antiferromagnetic layer increases as the amount of Pt increases. Therefore, by increasing the amount of Pt, the difference in lattice constant between the antiferromagnetic layer and the ferromagnetic layer can be widened, and the interface between the antiferromagnetic layer and the ferromagnetic layer can be easily brought into a mismatched state.
[0354]
  On the other hand, the crystal orientation of each layer such as the antiferromagnetic layer formed on the seed layer by forming the seed layer below the antiferromagnetic layer as in the film configuration described above is the same as that of the seed layer. In a direction parallel to the film surface{111}It becomes easy to preferentially orient the plane.
[0355]
Also, the larger the amount of Pt, the better. This is because if the amount of Pt is excessively large, the antiferromagnetic layer cannot cause proper ordered transformation even if heat treatment is performed.
[0356]
In the present invention, the seed layer is laid on the lower side of the antiferromagnetic layer, and the Pt amount constituting the antiferromagnetic layer is likely to undergo regular transformation, and the interface with the ferromagnetic layer is easily maintained in an inconsistent state. Due to the formation of the composition, when the heat treatment is performed, the antiferromagnetic layer undergoes an appropriate ordered transformation while maintaining an inconsistent state at the interface with the ferromagnetic layer, and in the state after the heat treatment, the antiferromagnetic layer In the ferromagnetic layer and the ferromagnetic layer, the same equivalent crystal plane is preferentially oriented in a direction parallel to the film surface, and at least a part of the same equivalent crystal axis direction existing in the crystal plane is the anti-strength. The magnetic layer and the ferromagnetic layer have crystal orientations facing in different directions.
[0357]
Further, when a cross section obtained by cutting the antiferromagnetic layer and the ferromagnetic layer from a direction parallel to the film thickness is observed, the crystal grain boundary of the antiferromagnetic layer and the crystal grain boundary of the ferromagnetic layer are This is a discontinuous state at least at a part of the interface between the magnetic layer and the ferromagnetic layer.
[0358]
【The invention's effect】
As described in detail above, in the exchange coupling film according to the present invention, the crystal planes oriented in the direction parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer are preferentially aligned with each other and exist in the crystal plane. In this case, at least a part of the same crystal axis is directed in different directions in the antiferromagnetic layer and the ferromagnetic layer.
[0359]
When such crystal orientation occurs, the antiferromagnetic layer has undergone appropriate regular transformation by heat treatment, and a large exchange coupling magnetic field can be obtained compared to the conventional case.
[0360]
In the present invention, it is preferable to form a seed layer below the antiferromagnetic layer. By providing the seed layer, the crystal orientation of the antiferromagnetic layer and the ferromagnetic layer formed on the seed layer can be preferentially oriented in the same crystal plane in a direction parallel to the film surface. Further, when the same crystal plane is preferentially oriented in the direction parallel to the film surface, the antiferromagnetic layer and the ferromagnetic layer can increase the resistance change rate.
[0361]
The above-described exchange coupling film can be applied to various magnetoresistive effect elements, and the magnetoresistive effect element having the exchange coupling film can appropriately cope with future higher recording density.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a structure of a single spin-valve magnetoresistive element according to a first embodiment of the present invention, viewed from the ABS surface side;
FIG. 2 is a cross-sectional view of the structure of a single spin-valve magnetoresistive element according to a second embodiment of the present invention as viewed from the ABS side;
FIG. 3 is a cross-sectional view of the structure of a single spin-valve magnetoresistive element according to a third embodiment of the present invention as viewed from the ABS side;
FIG. 4 is a cross-sectional view of the structure of a single spin-valve magnetoresistive effect element according to a fourth embodiment of the present invention as viewed from the ABS side;
FIG. 5 is a cross-sectional view of the structure of a dual spin valve magnetoresistive effect element according to a fifth embodiment of the present invention as viewed from the ABS side;
FIG. 6 is a cross-sectional view of the structure of an AMR magnetoresistive element according to a sixth embodiment of the present invention viewed from the ABS side;
FIG. 7 is a cross-sectional view of the structure of an AMR magnetoresistive element according to a seventh embodiment of the present invention, viewed from the ABS surface side;
FIG. 8 is a schematic diagram showing the state of the magnetoresistive element shown in FIG.
9 is a schematic diagram showing a structure of the laminated film after heat treatment is performed on the laminated film shown in FIG.
10 is a schematic diagram showing a state of a film formation stage of the magnetoresistive effect element shown in FIG.
11 is a schematic view showing the structure of the laminated film after heat treatment is performed on the laminated film shown in FIG.
FIG. 12 is a partial cross-sectional view showing the structure of a thin film magnetic head (reproducing head) in the present invention;
FIG. 13 is a graph showing the relationship between the Pt amount and the exchange coupling magnetic field (Hex) when the Pt amount of the antiferromagnetic layer (PtMn alloy film) is changed;
FIG. 14 is a diagram schematically showing the crystal orientation of the antiferromagnetic layer and the ferromagnetic layer of the exchange coupling film in the present invention;
FIG. 15 is a diagram schematically showing the crystal orientation of an antiferromagnetic layer and a ferromagnetic layer of an exchange coupling film in a comparative example;
FIG. 16 is a transmission electron diffraction image from a direction parallel to the film surface of the spin valve film in the present invention;
FIG. 17 is a transmission electron diffraction image from a direction parallel to the film surface of a spin valve film in a comparative example;
FIG. 18 is a partial schematic diagram of the transmission electron beam diffraction image shown in FIG.
FIG. 19 is a partial schematic diagram of the transmission electron beam diffraction image shown in FIG.
FIG. 20 is a schematic diagram of a transmission electron beam diffraction image from a direction perpendicular to the film surface of the antiferromagnetic layer in the present invention;
FIG. 21 is a schematic diagram of a transmission electron beam diffraction image from a direction perpendicular to the film surface of the ferromagnetic layer in the present invention;
22 is a schematic diagram in which the transmission electron diffraction images of FIGS. 20 and 21 are superimposed,
FIG. 23 is a schematic diagram of a transmission electron diffraction image from a direction perpendicular to the film surface of the antiferromagnetic layer in a comparative example;
FIG. 24 is a schematic diagram of a transmission electron beam diffraction image from a direction perpendicular to the film surface of a ferromagnetic layer in a comparative example;
FIG. 25 is a schematic diagram in which the transmission electron diffraction images of FIGS.
FIG. 26 is a transmission electron micrograph of the cut surface of the spin valve thin film element according to the present invention cut from a direction parallel to the film thickness;
FIG. 27 is a transmission electron micrograph of the cut surface when a spin valve thin film element in a comparative example was cut from a direction parallel to the film thickness;
FIG. 28 is a partial schematic diagram of the transmission electron micrograph shown in FIG.
FIG. 29 is a partial schematic diagram of the transmission electron micrograph shown in FIG. 27;
[Explanation of symbols]
1 Free magnetic layer
2 Nonmagnetic intermediate layer
3 Pinned magnetic layer (ferromagnetic layer)
4 Antiferromagnetic layer
5 Hard bias layer
6 Underlayer
7 Protective layer
8 Conductive layer
14, 23 First antiferromagnetic layer
15, 24 Second antiferromagnetic layer
16, 21 Exchange bias layer
17, 26 Insulating layer
18 Soft magnetic layer (SAL layer)
19 Nonmagnetic layer (SHUNT layer)
20 Magnetoresistive layer (MR layer)
22 Seed layer
25 Third antiferromagnetic layer
42 Magnetoresistive element

Claims (24)

Exchange coupling in which an antiferromagnetic layer is formed in contact with a ferromagnetic layer, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is made constant. In the membrane,
The antiferromagnetic layer is formed of an antiferromagnetic material containing element X (where X is one or more of Pt, Pd, Ir, Rh, Ru, and Os) and Mn. And
The crystal plane parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer is preferentially oriented to the same equivalent crystal plane, and at least a part of the same equivalent crystal axis existing in the crystal plane is the An exchange coupling film, wherein the antiferromagnetic layer and the ferromagnetic layer are oriented in different directions.   The exchange coupling film according to claim 1, wherein the crystal plane is an equivalent crystal plane typically represented as a {111} plane.   3. The exchange coupling film according to claim 2, wherein the direction of the crystal axis is an equivalent crystal axis direction typically represented as a <110> direction. Exchange coupling in which an antiferromagnetic layer is formed in contact with a ferromagnetic layer, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is made constant. In the membrane,
In the transmission electron beam diffraction images of the antiferromagnetic layer and the ferromagnetic layer obtained by making an electron beam incident from a direction parallel to the interface, diffraction spots corresponding to reciprocal lattice points representing each crystal plane of each layer are obtained. Appear,
Among the diffraction spots, the diffraction spots of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer are indexed the same and located in the film thickness direction when viewed from the beam origin. The first imaginary line connecting the beam origin coincides with the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer,
The second imaginary line connecting the diffraction spot showing a certain crystal plane and the beam origin, which is the same indexing and is located in a direction other than the film thickness direction when viewed from the beam origin, is an antiferromagnetic An exchange coupling film, wherein the diffraction image of the layer and the diffraction image of the ferromagnetic layer are shifted from each other. Exchange coupling in which an antiferromagnetic layer is formed in contact with a ferromagnetic layer, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is made constant. In the membrane,
In the transmission electron beam diffraction images of the antiferromagnetic layer and the ferromagnetic layer obtained by making an electron beam incident from a direction parallel to the interface, diffraction spots corresponding to reciprocal lattice points representing each crystal plane of each layer are obtained. Appear,
Among the diffraction spots, the diffraction spots of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer are indexed the same and located in the film thickness direction when viewed from the beam origin. The first imaginary line connecting the beam origin coincides with the diffraction image of the antiferromagnetic layer and the diffraction image of the ferromagnetic layer,
When viewed from the beam origin, a diffraction spot indicating a crystal plane located in a direction other than the film thickness direction appears only in one of the diffraction images of the antiferromagnetic layer or the ferromagnetic layer, and Exchange coupling membrane.   The exchange coupling film according to claim 4 or 5, wherein the diffraction spots located in the film thickness direction show an equivalent crystal plane typically represented as a {111} plane. Exchange coupling in which an antiferromagnetic layer is formed in contact with a ferromagnetic layer, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is made constant. In the membrane,
In the transmission electron beam diffraction images of the antiferromagnetic layer and the ferromagnetic layer obtained by making the electron beam incident from the direction perpendicular to the interface, diffraction spots corresponding to reciprocal lattice points representing the crystal planes of the respective layers are obtained. Appear,
Among the diffraction spots, an imaginary line connecting the diffraction spot of the antiferromagnetic layer and the diffraction pattern of the ferromagnetic layer, from the diffraction spot to the beam origin, is a diffraction image of the antiferromagnetic layer. And the diffraction pattern of the ferromagnetic layer are deviated from each other. Exchange coupling in which an antiferromagnetic layer is formed in contact with a ferromagnetic layer, an exchange coupling magnetic field is generated at the interface between the antiferromagnetic layer and the ferromagnetic layer, and the magnetization direction of the ferromagnetic layer is made constant. In the membrane,
In the transmission electron beam diffraction images of the antiferromagnetic layer and the ferromagnetic layer obtained by making the electron beam incident from the direction perpendicular to the interface, diffraction spots corresponding to reciprocal lattice points representing the crystal planes of the respective layers are obtained. Appear,
Among the diffraction spots, diffraction spots with an index appear only in one of the diffraction images of the antiferromagnetic layer or the ferromagnetic layer,
The crystal plane parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer is preferentially oriented to the same equivalent crystal plane, and at least a part of the same equivalent crystal axis existing in the crystal plane is the An exchange coupling film, wherein the antiferromagnetic layer and the ferromagnetic layer are oriented in different directions.   9. The exchange coupling film according to claim 7, wherein the direction perpendicular to the interface is an equivalent crystal axis direction typically represented as a <111> direction. The exchange coupling film according to claim 7 or 8, wherein a crystal plane parallel to the interface between the antiferromagnetic layer and the ferromagnetic layer is an equivalent crystal plane typically represented as a { 111 } plane. The exchange coupling film is laminated in the order of an antiferromagnetic layer and a ferromagnetic layer from below, and below the antiferromagnetic layer, the crystal structure is mainly composed of face-centered cubic crystals and is parallel to the interface. 11. The exchange coupling film according to claim 1, wherein a seed layer in which an equivalent crystal plane represented as a { 111 } plane is preferentially oriented is formed.   The seed layer is formed of a NiFe alloy or a Ni-Fe-Y alloy (where Y is at least one selected from Cr, Rh, Ta, Hf, Nb, Zr, and Ti). Exchange coupling membrane.   The exchange coupling film according to claim 11, wherein the seed layer is nonmagnetic at room temperature.   The underlayer formed of at least one element selected from Ta, Hf, Nb, Zr, Ti, Mo, and W is formed under the seed layer. Exchange coupling membrane.   The exchange coupling film according to claim 11, wherein at least a part of the interface between the antiferromagnetic layer and the seed layer is in an inconsistent state.   The antiferromagnetic layer includes elements X and X ′ (wherein element X ′ is Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti, V, Cr, Fe). , Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, and one or more elements among rare earth elements The exchange coupling film according to any one of claims 1 to 15, wherein the exchange coupling film is formed of Mn.   The antiferromagnetic material is an interstitial solid solution in which an element X ′ penetrates into a space between spatial lattices composed of elements X and Mn, or a lattice point of a crystal lattice composed of elements X and Mn. The exchange coupling film according to claim 16, wherein a part thereof is a substitutional solid solution substituted with element X ′.   18. The exchange coupling film according to claim 1, wherein a composition ratio (atomic%) of the element X or the element X + X ′ is 45 (at%) or more and 60 (at%) or less.   19. The exchange coupling film according to claim 1, wherein at least a part of the interface between the antiferromagnetic layer and the ferromagnetic layer is in an inconsistent state. An antiferromagnetic layer, a ferromagnetic layer formed in contact with the antiferromagnetic layer, the magnetization direction of which is fixed by an exchange anisotropic magnetic field with the antiferromagnetic layer, and a nonmagnetic intermediate layer on the ferromagnetic layer In a magnetoresistive element having a free magnetic layer formed via a bias layer that aligns the magnetization direction of the free magnetic layer in a direction crossing the magnetization direction of the ferromagnetic layer,
The antiferromagnetic layer and the ferromagnetic layer formed in contact with the antiferromagnetic layer are formed of the exchange coupling film according to any one of claims 1 to 19. Magnetoresistive effect element. An antiferromagnetic layer, a ferromagnetic layer formed in contact with the antiferromagnetic layer, the magnetization direction of which is fixed by an exchange anisotropic magnetic field with the antiferromagnetic layer, and a nonmagnetic intermediate layer on the ferromagnetic layer A magnetoresistive effect element having an antiferromagnetic exchange bias layer formed on the upper or lower side of the free magnetic layer and spaced apart in the track width direction. ,
The antiferromagnetic layer and the ferromagnetic layer are formed of the exchange coupling film according to any one of claims 1 to 19, and the magnetization of the free magnetic layer is set in a certain direction. Magnetoresistive effect element. A nonmagnetic intermediate layer stacked above and below a free magnetic layer, a ferromagnetic layer located above one of the nonmagnetic intermediate layers and below the other nonmagnetic intermediate layer, and above the one ferromagnetic layer and Located under the other ferromagnetic layer, an antiferromagnetic layer that fixes the magnetization direction of each ferromagnetic layer in a fixed direction by an exchange anisotropic magnetic field, and the magnetization direction of the free magnetic layer In a magnetoresistive element having a bias layer aligned with a direction crossing the magnetization direction of the layer,
The antiferromagnetic layer and the ferromagnetic layer formed in contact with the antiferromagnetic layer are formed of the exchange coupling film according to any one of claims 1 to 19. Magnetoresistive effect element. The magnetoresistive layer includes a magnetoresistive layer and a soft magnetic layer that are stacked with a nonmagnetic layer interposed therebetween. In a magnetoresistive element with an antiferromagnetic layer formed,
A magnetoresistive effect element, wherein the antiferromagnetic layer and the magnetoresistive layer are formed of the exchange coupling film according to any one of claims 1 to 19.   24. A thin film magnetic head, wherein shield layers are formed above and below the magnetoresistive effect element according to claim 20 via a gap layer.

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